diff --git a/APlusB.cpp b/APlusB.cpp
new file mode 100644
index 0000000..a4bcb4f
--- /dev/null
+++ b/APlusB.cpp
@@ -0,0 +1,14 @@
+#include <iostream>
+int a=2;
+int sum_of_two_digits(int first_digit, int second_digit) {
+    return first_digit + second_digit;
+}
+
+int main() {
+    int a = 0;
+    int b = 0;
+    std::cin >> a;
+    std::cin >> b;
+    std::cout << sum_of_two_digits(a, b);
+    return 0;
+}
diff --git a/AboutMe.md b/AboutMe.md
new file mode 100644
index 0000000..3e6804d
--- /dev/null
+++ b/AboutMe.md
@@ -0,0 +1,2 @@
+I am Varun Sharma.
+I am Excel Blaze.
diff --git a/ApileOFStones b/ApileOFStones
new file mode 100644
index 0000000..374b21a
Binary files /dev/null and b/ApileOFStones differ
diff --git a/BicoloredRBS b/BicoloredRBS
new file mode 100644
index 0000000..0bd2890
Binary files /dev/null and b/BicoloredRBS differ
diff --git a/DIV2A.cpp b/DIV2A.cpp
new file mode 100644
index 0000000..fc29080
--- /dev/null
+++ b/DIV2A.cpp
@@ -0,0 +1,75 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int n;
+    cin>>n;
+
+    int a[n];
+
+    int flag=0;
+
+    for(int i=0;i<n;i++)
+    {
+        cin>>a[i];
+        if(a[i]>=0)
+        {
+            a[i]=-a[i]-1;
+            if(a[i]!=-1)
+            flag=1;
+        }
+    }
+
+
+    if(flag==1)
+    {
+        if(n%2==0)
+        {
+            for(int i=0;i<n;i++)
+            {
+                cout<<a[i]<<" ";
+            }
+        }
+        else
+        {
+            vector<int> v;
+            for(int i=0;i<n;i++)
+            {
+                if(a[i]!=-1)
+                v.push_back(a[i]);
+
+            }
+
+            sort(v.begin(),v.end());
+            int last=v[v.size()-1];
+            int g=0;
+            for(int i=0;i<n;i++)
+            {
+                if(a[i]==last&&g==0)
+                {
+                    a[i]=-a[i]-1;
+                    g=1;
+                }
+
+                cout<<a[i]<<" ";
+            }
+        }
+
+    }
+    else
+    {
+        if(n%2==0)
+        {
+            for(int i=0;i<n;i++)
+            cout<<a[i]<<" ";
+        }
+        else
+        {
+            cout<<0<<" ";
+            for(int i=1;i<n;i++)
+            cout<<a[i]<<" ";
+        }
+    }
+}
diff --git a/DIV2B.cpp b/DIV2B.cpp
new file mode 100644
index 0000000..fc29080
--- /dev/null
+++ b/DIV2B.cpp
@@ -0,0 +1,75 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int n;
+    cin>>n;
+
+    int a[n];
+
+    int flag=0;
+
+    for(int i=0;i<n;i++)
+    {
+        cin>>a[i];
+        if(a[i]>=0)
+        {
+            a[i]=-a[i]-1;
+            if(a[i]!=-1)
+            flag=1;
+        }
+    }
+
+
+    if(flag==1)
+    {
+        if(n%2==0)
+        {
+            for(int i=0;i<n;i++)
+            {
+                cout<<a[i]<<" ";
+            }
+        }
+        else
+        {
+            vector<int> v;
+            for(int i=0;i<n;i++)
+            {
+                if(a[i]!=-1)
+                v.push_back(a[i]);
+
+            }
+
+            sort(v.begin(),v.end());
+            int last=v[v.size()-1];
+            int g=0;
+            for(int i=0;i<n;i++)
+            {
+                if(a[i]==last&&g==0)
+                {
+                    a[i]=-a[i]-1;
+                    g=1;
+                }
+
+                cout<<a[i]<<" ";
+            }
+        }
+
+    }
+    else
+    {
+        if(n%2==0)
+        {
+            for(int i=0;i<n;i++)
+            cout<<a[i]<<" ";
+        }
+        else
+        {
+            cout<<0<<" ";
+            for(int i=1;i<n;i++)
+            cout<<a[i]<<" ";
+        }
+    }
+}
diff --git a/DIV2C.cpp b/DIV2C.cpp
new file mode 100644
index 0000000..963feed
--- /dev/null
+++ b/DIV2C.cpp
@@ -0,0 +1,69 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    long long int n,q;
+    cin>>n>>q;
+
+    long long int a[n];
+    for(int i=0;i<n;i++)
+    cin>>a[i];
+
+    long long int find1[n];
+    long long int max1=a[0];
+
+    long long int maxi=0;
+    long long int maxe=a[0];
+
+    for(int i=0;i<n;i++)
+    {
+        max1=max(max1,a[i]);
+        find1[i]=max1;
+
+        if(a[i]>maxe)
+        {
+            maxe=a[i];
+            maxi=i;
+        }
+    }
+int b[n];
+copy(a,a+n,b);
+ for(int i=0;i<maxi;i++)
+    {
+        if(b[i]>b[i+1])
+        {
+            int temp=b[i];
+            b[i]=b[i+1];
+            b[i+1]=temp;
+      }
+      }
+    vector<long long int> v;
+    for(int i=(maxi+1)%n;i!=maxi;i=(i+1)%n)
+    {
+        v.push_back(b[i]);
+    }
+
+    long long int m;
+
+
+    //for(int j=0;j<v.size();j++)
+    //cout<<v[j]<<" ";
+    while(q--)
+    {
+        cin>>m;
+
+        if(m<=maxi)
+        {
+            cout<<find1[m-1]<<" "<<a[m]<<"\n";
+        }
+        else
+        {
+            m=m-maxi-1;
+            m=(m%(n-1));
+            cout<<maxe<<" "<<v[m]<<"\n";
+        }
+    }
+
+}
diff --git a/DIV3B.cpp b/DIV3B.cpp
new file mode 100644
index 0000000..143c33e
--- /dev/null
+++ b/DIV3B.cpp
@@ -0,0 +1,41 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        int n;
+        cin>>n;
+        int a[n];
+        int m0=0,m1=0,m2=0;
+        for(int i=0;i<n;i++)
+        {
+            cin>>a[i];
+            if(a[i]%3==0)
+            m0++;
+            else if(a[i]%3==1)
+            m1++;
+            else
+            m2++;
+
+
+        }
+
+        if(m1>m2)
+        {
+            m1=m1-m2;
+            cout<<m0+m2+m1/3<<"\n";
+        }
+        else
+        {
+            m2=m2-m1;
+            cout<<m0+m1+m2/3<<"\n";
+        }
+
+
+    }
+}
diff --git a/DIV3B.o b/DIV3B.o
new file mode 100644
index 0000000..152ffb2
Binary files /dev/null and b/DIV3B.o differ
diff --git a/DIV3D b/DIV3D
new file mode 100644
index 0000000..eb70de0
Binary files /dev/null and b/DIV3D differ
diff --git a/GUI2 b/GUI2
new file mode 100644
index 0000000..52a9511
--- /dev/null
+++ b/GUI2
@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+#include <algorithm>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+#define ass 1e18
+#define MOD 1000000007
+#define mp make_pair
+#define pb push_back
+#define fi first
+#define se second
+#define boost ios_base::sync_with_stdio(false);cin.tie(NULL);
+#define debug(x) cout << #x << ": " << x << endl;
+#define debug2(x,y) cout<<#x<<": "<< x<< ", "<< #y<< ": "<< y<< endl;
+#define debug3(x,y,z) cout<<#x<<": "<< x<< ", "<< #y<< ": "<< y<<" "<<#z<<" : "<<z<< endl;
+using namespace std;
+typedef long long int ll;
+#include <ext/pb_ds/assoc_container.hpp> 
+#include <ext/pb_ds/tree_policy.hpp> 
+using namespace __gnu_pbds;   
+#define ordered_set tree<ll, null_type,less<ll>, rb_tree_tag,tree_order_statistics_node_update>
+ll arr[200005];
+
+int main()
+{
+	boost
+	ll t,ans,e1,e2,o1,o2,a,n,m,i;
+	cin>>t;
+	while(t--)
+	{
+		cin>>n;
+		e1=0;o1=0;e2=0;o2=0;
+		for(i=0;i<n;i++)
+		{
+			cin>>a;
+			if(a%2==0)
+				e1++;
+			else
+				o1++;
+		}
+		cin>>m;
+		for(i=0;i<m;i++)
+		{
+			cin>>a;
+			if(a%2==0)
+				e2++;
+			else
+				o2++;
+		}
+		ans=e1*e2+o1*o2;
+		cout<<ans<<"\n";
+	}
+	return 0;
+}
diff --git a/General.md b/General.md
new file mode 100644
index 0000000..87558eb
--- /dev/null
+++ b/General.md
@@ -0,0 +1 @@
+General details.
diff --git a/HackercupQ2.cpp b/HackercupQ2.cpp
new file mode 100644
index 0000000..e343d22
--- /dev/null
+++ b/HackercupQ2.cpp
@@ -0,0 +1,115 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+
+bool isprime(ll p)
+{
+	ll i;
+	for(i=2;i*i<=p;i++)
+	{
+		if(p%i==0)
+			return false;
+	}
+	return true;
+}
+
+int main()
+{
+	ll t;
+	cin>>t;
+	while(t--)
+	{
+		ll n,k,x;
+		cin>>n;
+		ll a[n],i,ans = 0;
+		for(i=0;i<n;i++)
+		{
+			cin>>a[i];
+			ans += a[i];
+		}
+		cin>>k>>x;
+		vector <ll> v;
+		for(i=0;i<n;i++)
+		{
+			ll b = a[i]^x;
+			b = b-a[i];
+			v.pb(b);
+		}
+		sort(v.begin(),v.end(),greater <ll>());
+		ll c1 = 0,sum = 0;
+		for(i=0;i<v.size();i++)
+		{
+			if(v[i]>=0)
+			{
+				c1++;
+				sum += v[i];
+			}
+			else
+				break;
+		}
+		ll index = i;
+		if(k<c1)
+		{
+			if((k^c1)%2==0)
+			{
+				cout<<ans+sum<<"\n";
+			}
+			else
+			{
+				if(index==n)
+				{
+					cout<<ans+sum-v[index-1]<<"\n";
+				}
+				else
+				{
+					if(v[index-1]>abst(v[index]))
+						cout<<sum+ans<<"\n";
+					else
+						cout<<ans+sum-v[index-1]<<"\n";
+				}
+			}
+		}
+		else if(k==c1)
+		{
+			cout<<ans+sum<<"\n";
+		}
+		else
+		{
+			ll c = 0;
+			while(c<(k-c1))
+			{
+				sum += v[index];
+				index++;
+				c++;
+			}
+			if(sum>0)
+				cout<<ans+sum<<"\n";
+			else
+				cout<<ans<<"\n";
+		}
+	}
+}
\ No newline at end of file
diff --git a/Killers.md b/Killers.md
new file mode 100644
index 0000000..f75ee22
--- /dev/null
+++ b/Killers.md
@@ -0,0 +1 @@
+I will slay them all.
diff --git a/Manthan19A.cpp b/Manthan19A.cpp
new file mode 100644
index 0000000..61f2fab
--- /dev/null
+++ b/Manthan19A.cpp
@@ -0,0 +1,51 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{   
+    ll t;
+    cin>>t;
+    while(t--)
+    {
+        ll a,b,n;
+        cin>>a>>b>>n;
+        if(n%3==0)
+        {
+            cout<<a<<"\n";
+        }
+        else if(n%3==1)
+        {
+            cout<<b<<"\n";
+        }
+        else
+        {   
+            ll c = a^b;
+            cout<<c<<"\n";
+        }
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/Manthan19B.cpp b/Manthan19B.cpp
new file mode 100644
index 0000000..f46ea2f
--- /dev/null
+++ b/Manthan19B.cpp
@@ -0,0 +1,69 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll n;
+    cin>>n;
+    ll a[n];
+    ll i,j;
+    for(i=0;i<n;i++)
+        cin>>a[i];
+    unordered_map <ll,ll> m;
+    ll ans = n-1;
+    for(i=0;i<n;i++)
+    {
+        bool vp = true;
+        for(j=0;j<i;j++)
+        {
+            m[a[j]]++;
+            if(m[a[j]]==2)
+            {
+                vp = false;
+                break;
+            }
+        }
+        ll su = n;
+        for(j=n-1;j>=i;j--)
+        {   
+            m[a[j]]++;
+            if(m[a[j]]==1)
+            {
+                su = j;
+            }
+            else
+                break;
+        }
+        if(vp)
+        {
+            ans = min(ans,su-i);
+        }
+        m.clear();
+    }
+    cout<<ans;
+    return 0;
+}
\ No newline at end of file
diff --git a/Manthan19C.cpp b/Manthan19C.cpp
new file mode 100644
index 0000000..2db804d
--- /dev/null
+++ b/Manthan19C.cpp
@@ -0,0 +1,91 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll n;
+    cin>>n;
+    ll a[4][4] = {{8,9,1,13},{3,12,7,5},{0,2,4,11},{6,10,15,14}};
+    ll b[n][n];
+    ll i,j;
+    ll c[n/2][n/2];
+    ll d = 0;
+    for(i=0;i<n/2;i++)
+    {
+        for(j=0;j<n/2;j++)
+        {
+            c[i][j] = d++;
+        }
+    }
+    for(i=0;i<n;i++)
+    {
+        for(j=0;j<n;j++)
+        {
+            if(i<n/2&&j>=n/2)
+            {
+                b[i][j] = c[i][j-n/2];
+            }
+            else if(i>=n/2&&j<n/2)
+            {
+                b[i][j] = c[i-n/2][j];
+            }
+            else if(i<n/2&&j<n/2)
+                b[i][j] = c[i][j];
+            else
+                b[i][j] = c[i-n/2][j-n/2];
+            
+        }
+    }
+    for(i=0;i<n;i++)
+    {
+        for(j=0;j<n;j++)
+        {
+            b[i][j] = 4*b[i][j];
+            if(i<n/2&&j<n/2)
+            {
+                b[i][j]++;
+            }
+            if(i<n/2&&j>=n/2)
+            {
+                b[i][j]+=2;
+            }
+            if(i>=n/2&&j<n/2)
+            {
+                b[i][j]+=3;
+            }
+        }
+    }
+    for(i=0;i<n;i++)
+    {
+        for(j=0;j<n;j++)
+        {
+            cout<<b[i][j]<<" ";
+        }
+        cout<<"\n";
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/Q1.cpp b/Q1.cpp
new file mode 100644
index 0000000..869c863
--- /dev/null
+++ b/Q1.cpp
@@ -0,0 +1,101 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll n;
+    cin>>n;
+    //ll x[2*n+2] = {0};
+    //ll y[2*n+2] = {0};
+    vector <ll> x[2*n+1],y[2*n+1];
+    ll a,b;
+    vector <pair<ll,ll>> v;
+    ll i;
+    for(i=1;i<=2*n+1;i++)
+    {
+        cin>>a>>b;
+        v.push_back({a,b});
+        x[a].pb(i);
+        y[b].pb(i);
+    }
+    ll vis[2*n+1] = {0};
+    ll j;
+    ll total = 0;
+    for(i=1;i<=2*n+1;i++)
+    {   
+        ll c1 = 0;
+        ll c2 = 0;
+        if(x[i].size()>1)
+        {
+            for(j=0;j<x[i].size();j++)
+            {
+                if(vis[x[i][j]]==0)
+                {
+                    vis[x[i][j]] = 1;
+                    c1++;
+                }
+            }
+        }
+        if(y[i].size()>1)
+        {
+            for(j=0;j<y[i].size();j++)
+            {
+                if(vis[y[i][j]]==0)
+                {
+                    vis[y[i][j]] = 1;
+                    c2++;
+                }
+            }
+        }
+        total += c1/2+c2/2;
+    }
+    cout<<total<<"\n";
+    /*for(i=0;i<v.size();i++)
+    {
+        a = v[i].first;
+        b = v[i].second;
+        ll c1 = 0;
+        ll c2 = 0;
+        if(x[a]%2==0)
+        {
+            c1++;
+        }
+        if(y[b]%2==0)
+        {
+            c2++;
+        }
+        if((total-(c1+c2))<n)
+        {
+            cout<<"NO\n";
+        }
+        else
+        {
+            cout<<"OK\n";
+        }
+    }*/
+    return 0;
+}
\ No newline at end of file
diff --git a/Q4.cpp b/Q4.cpp
new file mode 100644
index 0000000..d9b4296
--- /dev/null
+++ b/Q4.cpp
@@ -0,0 +1,62 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll t;
+    cin>>t;
+    ll n,m;
+    cin>>n>>m;
+    ll a[n][m],ans[n*m+1] = {0};
+    ll i,j;
+    for(i=1;i<=n*m;i++)
+    {
+        for(j=0;j<n*m;j+=i)
+        {
+            if(a[j/m][j%m]!=i)
+                ans[i]++;
+            a[j/m][j%m] = i;
+            if(a[j%n][j/n]!=i)
+                ans[i]++;
+            a[j%n][j/n] = i;
+        }
+    }
+    for(i=1;i<=n*m;i++)
+    {
+        cout<<ans[i]<<" ";
+        ans[i] = 0;
+    }
+    cout<<"\n";
+    for(i=0;i<n;i++)
+    {
+        for(j=0;j<m;j++)
+        {
+            a[i][j] = 0;
+        }
+    }  
+    return 0;
+}
\ No newline at end of file
diff --git a/Sam b/Sam
new file mode 100644
index 0000000..bfd155c
--- /dev/null
+++ b/Sam
@@ -0,0 +1 @@
+My first PR
diff --git a/a1.cpp b/a1.cpp
new file mode 100644
index 0000000..ea4c7d1
--- /dev/null
+++ b/a1.cpp
@@ -0,0 +1,19 @@
+#include<bits/stdc++.h>
+#define rep(k,n) for(int i=k;i<n;i++)
+using namespace std;
+int main()
+{
+	int ar[105],n,ans=0;
+	scanf("%d",&n);
+	rep(0,n)
+	scanf("%d",&ar[i]);
+	sort(ar,ar+n);
+	//rep(0,n)
+	//printf("%d",ar[i]);
+	rep(0,n)
+	{
+		i+=1;
+		ans+=ar[i]-ar[i-1];
+	}
+	printf("%d",ans);
+}
\ No newline at end of file
diff --git a/a2.cpp b/a2.cpp
new file mode 100644
index 0000000..17988cb
--- /dev/null
+++ b/a2.cpp
@@ -0,0 +1,39 @@
+#include<bits/stdc++.h>
+#define rep(k,n) for(int i=k;i<n;i++)
+using namespace std;
+int main()
+{
+	long long n,ar[200005],max=-1,sum=0,flag=0;
+	cin>>n;
+	rep(0,n)
+	cin>>ar[i];
+	rep(0,n)
+	{
+		if(ar[i]>max)
+			max=ar[i];
+		sum+=ar[i];
+	}
+	if((max*n-sum)%2==1)
+	{
+		if(n%2==1)
+			max++;
+		else
+			flag=1;
+	}
+	rep(0,n)
+	{
+		if((max-ar[i])%2==0)
+			continue;
+		else
+		{
+			if((ar[i]-ar[i+1])%2==0)
+				ar[i+1]++;
+			else
+				flag=1;
+		}
+	}
+	if(flag==0)
+		printf("YES");
+	else
+		printf("NO");
+}
\ No newline at end of file
diff --git a/a3.cpp b/a3.cpp
new file mode 100644
index 0000000..2b4ea15
--- /dev/null
+++ b/a3.cpp
@@ -0,0 +1,140 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(k,n) for(int i=k;i<n;i++)
+#define ll long long
+using namespace std;
+ll ar[1000005];
+int main()
+{
+	/*long long n,ans=0,max=0,num=1,c;
+	cin>>n;
+	c=n;
+	if(n%2==0)
+	{
+		num=2;
+		while(n%2==0)
+			{
+				max++;
+				n/=2;
+			}	
+	}
+	for(int i=3;i<=sqrt(n);i+=2)
+	{
+		if(n%i==0)
+		{
+			while(n%i==0)
+			{
+				n/=i;
+				ans++;
+			}
+			num*=i;
+			if(ans>max)
+				max=ans;
+		}
+	}
+	if(n!=1)
+	{
+		num*=n;
+	}
+	ans=0;
+	printf("%d",num);
+	long long x=num,sqr;
+	sqr=num;
+	while(sqr<c)
+	{
+		sqr*=sqr;
+	}
+	if(sqr!=c)
+	ans++;
+	x=sqr;
+	//printf("S%d %d",(int)sqrt(x),(int)pow(x,0.5));
+	long long m=sqrt(x);
+	while(x!=1&&(m*m==x))
+	{
+	//printf("S%lld ",x);		
+		x=sqrt(x);
+
+		ans++;
+		m=sqrt(x);
+	}
+	printf(" %d",ans);*/
+	ll n,num=1,c,ans=0,l=0;
+	cin>>n;
+	c=n;
+	for(int i=0;i<=n;i++)
+	ar[i]=1;
+	for(int i=2;i<=n;i++)
+	{
+		if(ar[i]==1)
+		{
+			for(int j=2*i;j<=n;j++)
+				ar[j]=0;
+		}
+	}
+
+	//printf("X%lld ",ar[0]);
+	for(int i=2;i<=c;i++)
+	{
+		ar[i]=0;
+		if(n%i==0)
+		{
+			while(n%i==0)
+			{
+				ar[i]++;
+				n/=i;
+			}
+			num*=i;
+		}
+	}
+	n=c;
+
+	ll flag=0,max=-1,sqr=2;
+	rep(2,n+1)
+	{
+		//printf("Z%lld ",ar[i]);
+		if(max<ar[i])
+		{
+			if(max>0)
+				flag=1;
+			max=ar[i];	
+		}				
+		if(ar[i]!=0&&max!=ar[i])
+		{
+			//printf("M%lld ",i);
+			flag=1;		
+		}
+	
+
+	}
+	if(max==1||max==0||max==-1)
+		printf("%lld %lld",n,0LL);
+	else
+	{
+		ans=0;
+		while(sqr<max)
+			sqr*=2;
+		if(flag!=0||max!=sqr)
+			ans++;
+		//printf("A%lld %lld %lld ",max,sqr,flag);
+		while(sqr!=1)
+			{
+				sqr/=2;
+				ans++;
+			}
+		printf("%lld %lld",num,ans);	
+	}
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/a4.cpp b/a4.cpp
new file mode 100644
index 0000000..2772e85
--- /dev/null
+++ b/a4.cpp
@@ -0,0 +1,35 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+using namespace std;
+ll ar[1000005];
+int main()
+{
+	int n,q,x,y;
+	int ar[100005];
+	char str[100005];
+	scanf("%d %d",&n,&q);
+	getchar();
+	ar[0]=0;
+	rep(1,n+1)
+	{
+		str[i]=getchar();
+		if(str[i]=='1')
+			ar[i]=1;
+		else
+			ar[i]=0;
+		ar[i]+=ar[i-1];
+	}
+	long long ans,po[100005];
+	po[0]=1;
+	for(int i=1;i<=n;i++)
+			po[i]=(2*po[i-1])%MOD;
+	for(int i=0;i<q;i++)
+	{
+		scanf("%d %d",&x,&y);
+		ans=(((po[ar[y]-ar[x-1]]-1)*(po[y-x+1-(ar[y]-ar[x-1])])))%MOD;
+		printf("%lld\n",ans);
+	}
+}
\ No newline at end of file
diff --git a/adjancencylist.cpp b/adjancencylist.cpp
new file mode 100644
index 0000000..a454a2c
--- /dev/null
+++ b/adjancencylist.cpp
@@ -0,0 +1,51 @@
+// creating adjacency list using vector 
+// vector is cache friendly
+
+#include<iostream>
+#include<bits/stdc++.h>
+using namespace std;
+
+
+
+
+void addlst(vector<int> a[], int u,int v){
+
+
+
+a[u].push_back(v);
+a[v].push_back(u);
+
+}
+
+
+void printt(vector<int> a[], int v){
+
+    for(int i=0;i<v;i++){
+
+        cout<<"The Adjacency list is "<<i<<" of head is \n";
+
+        for(int m: a[i]){
+cout<<m;
+
+printf("\n");
+        }
+    }
+}
+
+
+int main(){
+
+    int v=8;
+   
+   vector<int>*a= new vector<int> [v];
+   addlst(a, 0, 1); 
+    addlst(a, 0, 4); 
+    addlst(a, 1, 2); 
+    addlst(a, 1, 3); 
+    addlst(a, 1, 4); 
+    addlst(a, 2, 3); 
+    addlst(a, 3, 4); 
+printt(a,v);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/adjancencylist.exe b/adjancencylist.exe
new file mode 100644
index 0000000..fd4cf62
Binary files /dev/null and b/adjancencylist.exe differ
diff --git a/agg.cpp b/agg.cpp
new file mode 100644
index 0000000..b59bd7f
--- /dev/null
+++ b/agg.cpp
@@ -0,0 +1,77 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007LL
+#define ROD 100000000ll
+#define INF 123456789123456ll
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+#define mp make_pair
+#define  piii pair<pair<ll,ll>,pair<ll,ll>>
+#define pii pair<ll,ll>
+#define fi first
+#define se second
+ll n,k,mr[200005],one,zero;
+char c;
+void mark(ll),unmark(ll);
+ll ans[200005],ar[200005];
+int main()
+{
+	scanf("%lld %lld",&n,&k);
+	rep(i,0,n)
+	{
+		scanf(" %c",&c);
+		ar[i]=(c=='W');
+	}
+
+	if(2*k+1>n)
+	{
+		ll f=1;
+		rep(i,0,n)
+		if(ar[i]==0)
+			zero++;
+		rep(i,0,n)
+		cout<<(zero<=one-zero)?'W':'B';
+	}
+	else
+	{
+		ll l=0,r=0;
+		mark(0);
+		rep(i,0,k)
+		{
+			l--;
+			r++;
+			mark(l);
+			mark(r);
+		}
+		rep(i,0,n)
+		{
+			//cout<<i<<" "<<one<<" "<<zero<<"\n";
+			cout<<(one>zero?'W':'B');
+			unmark(l);
+			l++;
+			r++;
+			mark(r);
+		}
+	}
+
+}
+void unmark(ll idx)
+{
+	idx%=n;
+	idx=(idx+n)%n;
+	if(ar[idx])
+		one--;
+	else
+		zero--;
+}
+void mark(ll idx)
+{
+	idx%=n;
+	idx=(idx+n)%n;
+	if(ar[idx])
+		one++;
+	else
+		zero++;
+}
\ No newline at end of file
diff --git a/alk.cpp b/alk.cpp
new file mode 100644
index 0000000..0910169
--- /dev/null
+++ b/alk.cpp
@@ -0,0 +1,125 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define ROD 1000000009
+#define INF 12345678
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define mp make_pair
+#define  pii pair <ll,ll> 
+ll n,m,x;
+int mem[1004][1004][6][2];
+char ar[1005][1005];
+ll func(ll,ll,ll,ll);
+int main()
+{
+	cin>>n>>m>>x;
+	x++;
+	rep(i,0,n)
+	{
+		scanf(" %s",ar[i]);
+	}
+	ll cnt=0;
+	memset(mem,-1,sizeof(mem));
+	if(n==1)
+	{
+		ll ans=0;
+		rep(i,0,m)
+		{
+			if(ar[0][i]=='#')
+			{
+				ans=-1;
+				break;
+			}
+			if(ar[0][i]=='*')
+				ans++;
+		}
+		if(m<=x)
+			cout<<ans;
+		else
+			cout<<"-1";
+		return 1;
+	}
+	ll ans=func(0,0,0,0);
+	if(ans<0)
+		cout<<"-1\n";
+	else
+	cout<<ans;
+}
+ll func(ll row,ll entr,ll exit,ll type)
+{
+	//cout<<row<<" "<<entr<<" "<<exit<<"\n";
+	if(exit>=x)
+		return -1*INF;
+	exit=entr+(type==1?1:-1)*exit;
+	if(mem[row][entr][exit][type]!=-1)
+		return mem[row][entr][exit][type];
+	if(row>=n)
+		return -1*INF;
+	if(row==n-1)
+	{
+		if(exit!=m-1||(m-1-entr)>=x)
+			return -1*INF;
+		ll cnt=0;
+		rep(i,entr,m)
+		{
+			if(ar[row][i]=='*')
+			cnt++;
+			if(ar[row][i]=='#')
+			return -1*INF;
+		}	
+		return cnt;
+	}	
+	if(row==0)
+	{
+		ll p=0;
+		rep(i,0,min(x,m))
+		{
+			if(ar[row][i]=='#')
+				break; 
+			p++;		
+		}	
+		ll temp,cnt=0,ans=-1*INF;
+		rep(i,0,p)
+		{
+			if(ar[row][i]=='*')
+				cnt++;
+			temp=cnt;
+			rep(j,0,p)
+			{
+				if(j>i&&ar[row][j]=='*')
+					cnt++;
+				//cout<<cnt<<"SS\n";
+				ans=max(ans,func(1,i,abs(j-i),j>i)+cnt);
+			}	
+			cnt=temp;
+		}	
+		return mem[row][entr][exit][type]=ans;
+	}
+	ll cnt1=0,cnt2=0,ans=-1*INF;
+	for(int i=entr;i<min(min(x+entr,x+exit),m);i++)
+	{
+		if(ar[row][i]=='#')
+			break;
+		if(ar[row][i]=='*')
+			cnt1++;
+		cnt2=0;
+		for(int j=exit;j<min(min(x+entr,x+exit),m);j++)
+		{
+			if(ar[row][j]=='#')
+				break;
+			if(j>i&&ar[row][j]=='*')
+				cnt2++;
+			ans=max(ans,func(row+1,i,abs(j-i),j>i)+cnt1+cnt2);
+			// if(cnt1+cnt2>1)
+			// cout<<cnt1<<"XXXXXXX"<<cnt2<<"\n";
+		}
+		return mem[row][entr][exit][type]=ans;
+	}
+}
\ No newline at end of file
diff --git a/alm.cpp b/alm.cpp
new file mode 100644
index 0000000..d973d0d
--- /dev/null
+++ b/alm.cpp
@@ -0,0 +1,71 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 998244353
+using namespace std;
+int  n,ar[100005];
+int mem[100005][205][2];
+ll func(ll,ll,ll);
+int main()
+{
+	cin>>n;
+	rep(i,0,n)
+	cin>>ar[i];
+	rep(i,0,n)
+	rep(j,0,205)
+	mem[i][j][0]=mem[i][j][1]=-1;
+	cout<<func(0,0,1);
+}
+ll func(ll idx,ll prev,ll set)
+{
+	//cout<<idx<<" "<<prev<<" "<<set<<"\n";
+	if(idx==n)
+	{
+		if(set==0)
+		return 0;
+		if(set==1)
+		return 1;
+	}
+	if(mem[idx][prev][set]!=-1)
+		return mem[idx][prev][set];
+	ll a=0,b=0,c=0;
+	if(ar[idx]==-1)
+	{
+		if(set==1)
+		{
+			rep(i,1,prev+1)
+			{
+				a+=func(idx+1,i,1);
+				a%=MOD;
+			}
+			rep(i,prev+1,201)
+			{
+				b+=func(idx+1,i,0);
+				b%=MOD;
+			}
+			return mem[idx][prev][set]=(int)((a+b)%MOD);
+		}	
+		if(set==0)
+		{
+			//if(idx==n-1)
+
+
+			rep(i,prev+1,201)
+			{
+				c+=func(idx+1,i,0);
+				c%=MOD;
+			}
+			c+=func(idx+1,prev,1);
+			c%=MOD;	
+			return mem[idx][prev][set]=(int)c;
+		}
+	}
+	if(ar[idx]<prev&&set==0)
+		return mem[idx][prev][set]=0;
+	if(ar[idx]>prev&&set==0)
+		return mem[idx][prev][set]=func(idx+1,ar[idx],0);
+	if(ar[idx]==prev&&set==0)
+		return mem[idx][prev][set]=func(idx+1,ar[idx],1);
+	return mem[idx][prev][set]=func(idx+1,ar[idx],ar[idx]<=prev);
+}
\ No newline at end of file
diff --git a/alo2.cpp b/alo2.cpp
new file mode 100644
index 0000000..1062b2f
--- /dev/null
+++ b/alo2.cpp
@@ -0,0 +1,70 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+
+
+ll t,n,ar[200005],br[200005];
+int main()
+{
+	cin>>t;
+	while(t--)
+	{
+		cin>>n;
+		rep(i,0,n)
+		cin>>ar[i];
+		sort(ar,ar+n);
+		br[0]=ar[n-1];
+		rep(i,0,n-1)
+		br[i+1]=ar[i];	
+		ll flag=0;
+		rep(i,2,n)
+		{
+			if(ar[i]!=(ar[i-1]+GCD(ar[i-1],ar[i-2])))
+			{
+				flag=1;
+			}
+		}
+		ll gflag=0;	
+		rep(i,2,n)
+		{
+			if(GCD(br[i-1],br[i-2])+br[i-1]!=br[i])
+				gflag=1;
+		}
+		if(n==1)
+		{
+			cout<<ar[0]<<"\n";
+			continue;
+		}
+		else if(n==2)
+		{
+			cout<<ar[1]<<" "<<ar[0]<<"\n";
+			continue;
+		}
+		else if(gflag==0)
+		{
+			rep(i,0,n)
+			cout<<br[i]<<" ";
+			cout<<"\n";
+			continue;
+		}
+		else if(flag==0)
+		{
+			rep(i,0,n)
+			cout<<ar[i]<<" ";
+			cout<<"\n";
+		}
+		else
+			cout<<"-1\n";
+	}
+}
+ll GCD(ll a,ll b)
+{
+	if(b==0)
+		return a;
+	return GCD(b,a%b);
+}
diff --git a/alp.cpp b/alp.cpp
new file mode 100644
index 0000000..257c0c2
--- /dev/null
+++ b/alp.cpp
@@ -0,0 +1,43 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000000LL
+#define INF 0x3f3f3f3f3f3f3f3f
+#define g 9.8
+#define MIN(a,b) (a>b?b:a)
+#define par 0.5
+using namespace std;
+ll func(ll);
+ll ar[2000005];
+int main()
+{
+	rep(i,1,2000005)
+	{
+		ar[i]=func(i);
+		ar[i]+=ar[i-1];
+	}
+	ll t;
+	//cout<<ar[2000000]<<" ";
+	cin>>t;
+	while(t--)
+	{
+		ll l,r;
+		cin>>l>>r;
+		if(l>r)
+			swap(l,r);
+		cout<<ar[r]-ar[l-1]<<"\n";
+	}
+}
+ll func(ll idx)
+{
+	ll  v,ans=0;
+	while(idx!=0)
+	{
+		v=idx%16;
+		idx/=16;
+		if(v>=10)
+			ans++;
+	}
+	return ans;
+}
\ No newline at end of file
diff --git a/alt.cpp b/alt.cpp
new file mode 100644
index 0000000..fc3d0a1
--- /dev/null
+++ b/alt.cpp
@@ -0,0 +1,69 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+ll flag,city[402],trk[250002][4],n,m,max_,full,endc,con;
+void func(ll);
+void bin(ll,ll);
+ll check(ll,ll,ll);
+int main()
+{
+	cin>>n>>m;
+	rep(i,1,n+1)
+	cin>>city[i];
+	rep(i,1,m+1)
+	{
+		rep(j,0,4)
+		cin>>trk[i][j];
+		func(i);
+	}
+	cout<<max_;
+}
+void func(ll idx)
+{
+	endc=trk[idx][1];
+	con=trk[idx][2];
+	if(check(trk[idx][0],max_,trk[idx][3])==0)
+	{
+		bin(idx,max_);
+	}
+}
+/*void bin(ll idx,ll low)
+{
+	ll high=(city[trk[idx][1]]-city[trk[idx][0]])*trk[idx][2],mid,ans;
+	endc=trk[idx][1];
+	con=trk[idx][2];	
+	while(low<=high)
+	{
+		mid=(low+high)/2;
+		full=mid;
+		flag=0;
+		if(check(trk[idx][0],mid,trk[idx][3]))
+		{
+			high=mid-1;
+			max_=mid;
+		}
+		else
+			low=mid+1;
+	}
+}*/
+ll check(ll c,ll fuel,ll r)
+{
+	if(flag==1||r<0)
+		return 0;
+	if(fuel<0)
+		return 0;
+	if(c==endc)
+	{
+		if(fuel>=0)
+		{
+			flag=1;
+			return 1;
+		}	
+	}
+	return check(c+1,fuel-(city[c+1]-city[c])*con,r)+check(c+1,full-(city[c+1]-city[c])*con,r-1);
+}
\ No newline at end of file
diff --git a/asd b/asd
new file mode 100644
index 0000000..4ba7f2f
Binary files /dev/null and b/asd differ
diff --git a/asd.cpp b/asd.cpp
new file mode 100644
index 0000000..967a082
--- /dev/null
+++ b/asd.cpp
@@ -0,0 +1,105 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+
+long long int facto(int n)
+{
+    long long int ans=1;
+    for(long long int i=1;i<=n;i++)
+    {
+        ans*=i;
+    }
+
+    return ans;
+}
+int nCr(int n, int r)
+{
+    return facto(n) / facto(n - r);
+}
+int solve(vector<int> &A, int B, int C) {
+
+    string str=to_string(C);
+    sort(A.begin(),A.end());
+    //map<int,int> mp;
+    if(B==1)
+    {
+        int count1=0;
+        for(int i=0;i<A.size();i++)
+        {
+            if(A[i]<C)
+            count1++;
+        }
+
+        return count1;
+    }
+
+    //for(int i=0;i<A.size();i++)
+    //{
+      //  mp[A[i]]=i+1;
+    //}
+    if(B<(str.length()))
+    {   //cout<<"$$";
+        if(A[0]==0)
+        {
+            return (A.size()-1)*facto(A.size()-1);
+        }
+        else
+        {
+            return facto(A.size());
+        }
+    }
+    if(B>str.length())
+    return 0;
+
+    long long int ans=0;
+    vector<int> removed;
+    for(int i=0;i<str.length();i++)
+    {
+        int no=(int)(str[i]-'0');
+       // cout<<no<<" "<<ans<<"\n";
+        if(i==0)
+        {
+            if(A[0]==0)
+            {
+                ans=ans+(lower_bound(A.begin(), A.end(),no)-A.begin()-1)*(nCr(A.size(),B-i-1));
+                //cout<<lower_bound(A.begin(), A.end(),no)-A.begin()<<"\n";
+
+            }
+            else
+            {
+                ans=ans + (lower_bound(A.begin(), A.end(),no)-A.begin())*(nCr(A.size(),B-i-1));
+            }
+        }
+        else
+        {
+           /* int count=0;
+            for(int j=0;j<removed.size();j++)
+            {
+                if(removed[j]<no)
+                count++;
+            }*/
+
+            ans=ans+(lower_bound(A.begin(), A.end(),no)-A.begin())*(nCr(A.size(),B-i-1));
+        }
+       // removed.push_back(no);
+    }
+
+    return ans;
+}
+
+int main()
+{
+    int n;
+    cin>>n;
+    vector<int> v(n);
+    for(int i=0;i<n;i++)
+    {
+        cin>>v[i];
+    }
+    int b;
+    cin>>b;
+    int c;
+    cin>>c;
+    cout<<solve(v,b,c)<<"\n";
+}
diff --git a/balanced.cpp b/balanced.cpp
new file mode 100644
index 0000000..166dba0
--- /dev/null
+++ b/balanced.cpp
@@ -0,0 +1,17 @@
+#include<iostream>
+
+#include<bits/stdc++.h>
+using namespace std;
+void areBal(string exp){
+
+
+
+}
+
+
+
+int main(){
+
+string a;
+
+}
\ No newline at end of file
diff --git a/bam.cpp b/bam.cpp
new file mode 100644
index 0000000..c8581c8
--- /dev/null
+++ b/bam.cpp
@@ -0,0 +1,72 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 1e19
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+void func();
+void tot(ll);
+ll ar[50005][2],mem[50005],n,b,size_,lim;
+int main()
+{
+	lim=log(1e19);
+	cin>>n>>b;
+	func();
+	rep(i,0,size_)
+	tot(i);
+	ll min_=(ll)INF;
+	rep(i,0,size_)
+	{
+		min_=min(min_,mem[i]/ar[i][1]);
+	}
+	cout<<min_;
+}
+void func()
+{
+	ll cnt=0;
+	while(b%2==0)
+	{
+		b/=2;
+		cnt++;
+	}
+	if(cnt!=0)
+	{
+		ar[size_][0]=2;
+		ar[size_++][1]=cnt;
+	}
+	cnt=0;
+	for(ll i=3;i<=sqrt(b);i+=2)
+	{
+		cnt=0;
+		// if(i==5)
+		// cout<<" "<<b%i<<"XYZ ";
+		if(b%i==0)
+		{
+			while(b%i==0)
+			{
+				cnt++;
+				b/=i;
+			}
+			ar[size_][0]=i;
+			ar[size_++][1]=cnt;		
+		}
+	}
+	if(b>1)
+	{
+		ar[size_][0]=b;
+		ar[size_++][1]=1;
+	}
+}
+void tot(ll idx)
+{
+	ll i=1,mul=ar[idx][0];
+	while((log(mul)*i)<=lim&&((n>=ar[idx][0])))
+	{
+		mem[idx]+=n/(ar[idx][0]);
+		ar[idx][0]*=mul;
+		i++;
+
+	}
+}
\ No newline at end of file
diff --git a/bes.cpp b/bes.cpp
new file mode 100644
index 0000000..f641adb
--- /dev/null
+++ b/bes.cpp
@@ -0,0 +1,52 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 998244353
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+ll func(ll,ll);
+void GCD(ll a,ll b);
+ll fac[100005],n,m,k,x,y,a,b;
+ll inv[100005];
+int main()
+{
+	cin>>n>>m>>k;
+	fac[0]=1;
+	rep(i,1,100005)
+	fac[i]=(fac[i-1]*i)%MOD;
+	
+	inv[0]=1;
+	rep(i,1,100004)
+	{
+		GCD(i,MOD);
+		inv[i]=x;
+	}
+	rep(i,1,100004)
+	{
+		inv[i]=(inv[i-1]*inv[i])%MOD;
+	}
+	ll ans=0;
+	rep(i,0,k)
+	{
+		cin>>a>>b;
+		ans+=(((((fac[n-a+b-1]*inv[n-a])%MOD)*inv[b-1])%MOD)*((((fac[a-1+m-b]*inv[a-1])%MOD)*inv[m-b])%MOD))%MOD;
+		ans%=MOD;
+	}
+	printf("%lld",(((((fac[n+m-2]*inv[n-1])%MOD)*inv[m-1])%MOD-ans)%MOD+MOD)%MOD);
+}
+
+void GCD(ll a,ll b)
+{
+	if(b==0)
+	{
+		x=1;
+		y=0;
+		return;
+	}
+	GCD(b,a%b);
+	ll temp=x;
+	x=y;
+	y=temp-(a/b)*y;
+}
\ No newline at end of file
diff --git a/bfsgrid.cpp b/bfsgrid.cpp
new file mode 100644
index 0000000..08f95c1
--- /dev/null
+++ b/bfsgrid.cpp
@@ -0,0 +1,93 @@
+#include<iostream>
+#include<bits/stdc++.h>
+using namespace std;
+
+int n;
+int m;
+vector<vector<int>>dis(n,vector<int>(m));
+
+vector<vector<int>>vis(1001,vector<int>(1001));
+
+
+bool isvalid(int sx,int sy){
+
+if(sx<0||sx>=n||sy<0||sx>=m){
+
+    return false;
+}
+
+if(vis[sx][sy]==1){
+
+    return false;
+}
+return true;
+
+}
+
+void bfs(int sx,int sy){
+if(sx<0||sx>=n||sy<0||sx>=m){
+
+    return;
+}
+
+if(vis[sx][sy]==1){
+
+    return;
+}
+
+queue<pair<int,int>> q;
+
+
+q.push({sx,sy});
+dis[sx][sy]=0;
+vis[sx][sy]=1;
+
+vector<int>dir={-1,0,1,0};
+vector<int>diry= {0,1,0,-1};
+while(!q.empty()){
+
+
+
+    int cx= q.front().first;
+    int cy= q.front().second;
+
+for(int i=0;i<4;i++)
+
+    if(isvalid(sx+dir[i],sy+diry[i])){
+
+
+
+int nx= sx+dir[i];
+int ny= sy+diry[i];
+
+dis[nx][ny]= dis[cx][cy]+1;
+vis[nx][ny]=1;
+q.push({nx,ny});
+
+
+    }
+
+
+}
+
+
+
+
+}
+
+
+
+int main(){
+int x, y;
+    cin>>n>>m;
+    cin>>x>>y;
+    bfs(x,y);
+
+    for(int i=0;i<dis.size();i++){
+    for(int j=0;j<dis[0].size();j++){
+
+cout<<dis[i][j]<<" ";
+    }
+    cout<<"\n";
+}
+}
\ No newline at end of file
diff --git a/bfsgrid.exe b/bfsgrid.exe
new file mode 100644
index 0000000..3ceb9af
Binary files /dev/null and b/bfsgrid.exe differ
diff --git a/bfsgrph.cpp b/bfsgrph.cpp
new file mode 100644
index 0000000..2c6662d
--- /dev/null
+++ b/bfsgrph.cpp
@@ -0,0 +1,90 @@
+#include<iostream>
+#include<bits/stdc++.h>
+using namespace std;
+
+class graph{
+public:
+
+int V;
+list<int>*adj;
+    graph(int V);
+    void add_edge(int u,int v);
+void bfs(int s);
+};
+
+graph::graph(int V){
+
+    this->V= V;
+    adj= new list<int>[V];
+
+}
+
+void graph:: add_edge(int u,int v){
+adj[u].push_back(v);
+}
+
+void graph:: bfs(int s){  ///bfs algorithm source gfg 
+
+    bool *visited= new bool[V];
+
+    for(int i=0;i<V;i++){
+
+        visited[i]= false;   // marked all node as not visited;
+    } 
+list<int>q;  // declaring queue for storing the vertices
+
+visited[s]= true;
+q.push_back(s);
+
+while(!q.empty()){
+
+s= q.front();
+
+cout<<s<<" ";
+q.pop_front(); //pop the front element from the queue 
+
+
+for(auto it= adj[s].begin();it!=adj[s].end();it++){
+// insert the neighbouring element into the queue and marked them visited
+
+    if(!visited[*it]){
+
+        visited[*it]= true;
+        q.push_back(*it);  // 10 17
+                           // 0 2 1 3 1 4 1 5 2 3 2 8 2 9 3 7 3 9 4 6 4 7 5 6 5 7 5 9 6 8 7 8 7 9
+    }
+}
+}
+}
+
+ int main(){
+
+     graph g(4);
+    //  g.add_edge(0,1);
+    //  g.add_edge(1,4);
+    //  g.add_edge(1,5);
+    //  g.add_edge(2,4);
+    //  g.add_edge(2,5);
+    //  g.add_edge(1,4);
+    //  g.add_edge(3,6);
+    //  g.add_edge(6,5);
+
+    //  cout<<"BFS traversal is given as \n";
+
+    //  g.bfs(0);
+
+
+
+     g.add_edge(0, 1); 
+    g.add_edge(0, 2); 
+    g.add_edge(1, 2); 
+    g.add_edge(2, 0); 
+    g.add_edge(2, 3); 
+    g.add_edge(3, 3); 
+  
+    cout << "Following is Breadth First Traversal "
+         << "(starting from vertex 2) \n"; 
+    g.bfs(2); 
+     return 0;
+
+ }
\ No newline at end of file
diff --git a/bfsgrph.exe b/bfsgrph.exe
new file mode 100644
index 0000000..cb55497
Binary files /dev/null and b/bfsgrph.exe differ
diff --git a/bol.cpp b/bol.cpp
new file mode 100644
index 0000000..7035d9b
--- /dev/null
+++ b/bol.cpp
@@ -0,0 +1,91 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define g 9.8
+#define MIN(a,b) (a>b?b:a)
+#define par 0.5
+using namespace std;
+ll n,m,ar[405],s,e,con,tot,max_,ans,str[402][402][2];
+ll check(ll);
+void findmax();
+void bin();
+int main()
+{
+	cin>>n>>m;
+	rep(i,1,n+1)
+	cin>>ar[i];
+	rep(i,0,m)
+	{
+		cin>>s>>e>>con>>tot;
+		if(str[s][e][0]==0||(tot<str[s][e][1])||(tot==str[s][e][1]&&con>str[s][e][0]))
+		{
+			str[s][e][0]=con;
+			str[s][e][1]=tot;		
+		}
+	}
+	rep(i,1,401)
+	rep(j,i,401)
+	{
+		if(str[i][j][0]!=0)
+		{
+			s=i;
+			e=j;
+			con=str[i][j][0];
+			tot=str[i][j][1];
+			bin();
+			//cout<<"HERE";
+		}
+	}
+	cout<<ans;
+
+}
+ll check(ll mid)
+{
+	ll prev=s;
+	ll cnt=0;
+	for(int i=s+1;i<=e;i++)
+	{
+		if(ar[i]-ar[prev]>mid)
+		{
+			prev=i-1;			
+			cnt++;
+		}
+	}
+	if(cnt>tot)
+		return 0;
+	return 1;
+}
+void findmax()
+{
+	ll prev=s;
+	max_=0;
+	for(int i=s+1;i<=e;i++)
+	{
+		if(ar[i]-ar[prev]>max_)
+			max_=ar[i]-ar[prev];
+		prev=i;
+	}	
+}
+void bin()
+{
+	findmax();
+	ll low=max_,high=ar[e]-ar[s],mid;
+	//if(e-s<=tot)
+	while(low<=high)
+	{
+		mid=(low+high)/2;
+		if(check(mid))
+		{
+			high=mid-1;
+			max_=mid;
+		}
+		else
+			low=mid+1;
+	}
+	//cout<<"HERE "<<max_<<" "<<con<<"\n";
+	if((max_*con)>ans)
+		ans=max_*con;
+}
\ No newline at end of file
diff --git a/bst.cpp b/bst.cpp
new file mode 100644
index 0000000..3b42368
--- /dev/null
+++ b/bst.cpp
@@ -0,0 +1,145 @@
+#include<iostream>
+#include<bits/stdc++.h>
+using namespace std;
+            struct node{
+            int data;
+            node *left;
+            node *right;
+            };
+
+node *root = NULL;
+
+node *getnode(int data){
+node *temp= new node();
+temp->data= data;
+temp->left=NULL;
+temp->right= NULL;
+return temp;
+
+}
+        class BST{
+        public:
+            node* insertbst(node *root, int data);
+            bool searchbst(node *root,int data);
+            void preorder(node *root);
+            void inorder(node *root);
+            void postorder(node *root);
+            int findheight(node *root);
+        };
+
+//function to insert
+node* BST:: insertbst(node *root,int data){
+
+//insert at root node
+if (root == NULL){
+root= getnode(data);
+return root;
+}
+//left node insertion
+else if(data <= root->data){
+    root->left= insertbst(root->left,data);
+
+}
+
+//right node insertion
+else{
+    root->right= insertbst(root->right,data);
+}
+return root;
+}
+            //searching in tree
+
+            bool BST:: searchbst(node *root,int data){
+            if (root== NULL){
+                return false;
+            }
+            else if(root->data ==data){
+                return true;
+            }
+            else if(data<= root->data){
+                return searchbst(root->left,data);
+            }
+            else{
+                return searchbst(root->right,data);
+            }
+            }
+//print left
+void BST ::preorder(node *root){
+if(root == NULL)
+{
+    return;
+}
+else{
+        cout<<root->data<<" ";
+    preorder(root->left);
+preorder(root->right);
+}
+cout<<endl;
+}
+        //print Inorder
+        void BST :: inorder(node *root)
+        {
+         if(root == NULL)
+        {
+            return;
+        }
+        else{
+
+            inorder(root->left);
+            cout<<root->data<<" ";
+            inorder(root->right);
+        }
+cout<<endl;
+        }
+//print Postorder
+void BST :: postorder(node *root){
+if (root == NULL){
+    return ;
+}
+else {
+    postorder(root->right);
+    postorder(root->left);
+    cout<<root->data<<" ";
+}
+
+}
+/*
+int BST :: findheight(node *root){
+if(root == NULL)
+    return -1;
+
+    int f= max(findheight(root->left),findheight(root->right))+1;
+cout<<&f;
+}*/
+
+//main function
+
+            int main(){
+                BST b;
+            root= b.insertbst(root,15);
+            root= b.insertbst(root,10);
+            root= b.insertbst(root,20);
+            root= b.insertbst(root,25);
+            root= b.insertbst(root,8);
+            root= b.insertbst(root,12);
+            cout<<"Preorder Traversal"<<endl;
+            b.preorder(root);
+            cout<<"Inorder Traversal"<<endl;
+            b.inorder(root);
+            cout<<"Postorder Traversal"<<endl;
+            b.postorder(root);
+            cout<<endl;
+cout<<"Height of tree"<<endl;
+//            b.findheight(root);
+
+            int n;
+            cout<<"Enter Number";
+            cin>>n;
+            if(b.searchbst(root,n)== true){
+                cout<<"found\n";
+
+            }
+            else cout<<"Not found\n";
+
+            return 0;
+            }
diff --git a/bst.exe b/bst.exe
new file mode 100644
index 0000000..dd468de
Binary files /dev/null and b/bst.exe differ
diff --git a/bst.o b/bst.o
new file mode 100644
index 0000000..020017d
Binary files /dev/null and b/bst.o differ
diff --git a/bst_oprcodechf.cpp b/bst_oprcodechf.cpp
new file mode 100644
index 0000000..c0af9e6
--- /dev/null
+++ b/bst_oprcodechf.cpp
@@ -0,0 +1,84 @@
+#include<iostream>
+#include<bits/stdc++.h>
+using namespace std;
+
+struct treeNode{
+
+
+    int data;
+
+    int p;
+    treeNode *left;
+    treeNode *right;
+
+};
+
+treeNode *getnode(int data){
+
+
+    treeNode *temp= new treeNode();
+
+    temp->data= data;
+    temp->left= nullptr;
+    temp->right= nullptr;
+    return temp;
+}
+
+
+
+class binarylst{
+
+public:
+
+treeNode* insert(int data,treeNode* root,int p){
+
+    if(root== NULL){
+cout<<p;
+cout<<"\n";
+
+        root= getnode(data);
+    }
+
+    else if(data<= root->data){
+
+        root= insert(data,root->left,2*p);
+    }
+    else{
+
+        root= insert(data,root->right,2*p+1);
+    }
+    return root;
+}
+
+
+void preorder(treeNode* root){
+    if(root== NULL){
+        return;
+    }
+    else{
+
+        cout<<root->data<<" ";
+        preorder(root->left);
+        preorder(root->right);
+    }
+}
+
+};
+
+
+int main(){
+treeNode* root= NULL;
+    binarylst b;
+
+
+vector<int> a={1,2,0,5};
+
+for(int i=0;i<a.size();i++)
+        root= b.insert(a[i],root,1);
+
+
+    cout<<"Preorder\n";
+    b.preorder(root);
+
+    return 0;
+}
diff --git a/bst_oprcodechf.exe b/bst_oprcodechf.exe
new file mode 100644
index 0000000..1dea5df
Binary files /dev/null and b/bst_oprcodechf.exe differ
diff --git a/bst_oprcodechf.o b/bst_oprcodechf.o
new file mode 100644
index 0000000..91d2974
Binary files /dev/null and b/bst_oprcodechf.o differ
diff --git a/c5.cpp b/c5.cpp
new file mode 100644
index 0000000..ec0a7cf
--- /dev/null
+++ b/c5.cpp
@@ -0,0 +1,69 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 998244353
+using namespace std;
+ll mem[10][10][1005],p[1005],s[1005],st[1005],ct[1005],t,n,k;
+ll func(ll,ll,ll);
+int main()
+{
+	cin>>t;
+	while(t--)
+	{
+		cin>>n>>k;
+		rep(i,0,n)
+		cin>>p[i];
+		rep(i,0,n)
+		cin>>s[i];
+		rep(i,0,n)
+		cin>>st[i];
+		rep(i,0,n)
+		cin>>ct[i];	
+		ll min=0x3f3f3f3f,ans=-1;
+		rep(i,0,10)
+		rep(j,0,10)
+		rep(k,0,1005)
+		mem[i][j][k]=-2;
+		rep(i,0,n)
+		{
+			if(p[i]==0)
+			{
+				ans=func(i,ct[i]-1,s[i]);
+				if(ans<min)
+				min=ans;
+			}	
+		}
+		printf("%lld\n",min<=1000?min:-1);
+	}
+}
+ll func(ll idx,ll left,ll pos)
+{
+	//cout<<idx<<" "<<left<<" "<<pos<<"\n";
+	if(left<0)
+	return 0x3f3f3f3f;
+	
+	if(mem[idx][left][pos]!=-2)
+	return mem[idx][left][pos];
+	
+	ll time_=st[idx]+(pos-p[idx])/s[idx];
+	ll ans=0x3f3f3f3f,min=0x3f3f3f3f;
+	ll flag=1;
+	
+	if(pos>=k)
+	return 0;
+	
+	if(ct!=0)
+	min=func(idx,left-1,pos+s[idx]);
+
+	rep(i,0,n)
+	{
+		if(i!=idx&&st[i]<=time_&&pos==p[i]+(time_-st[i])*s[i])
+		{
+			ans=1+func(i,ct[i]-1,pos+s[i]);
+			if(ans<min)
+				min=ans;			
+		}
+	}
+	return mem[idx][left][pos]=min;
+}
\ No newline at end of file
diff --git a/c6.cpp b/c6.cpp
new file mode 100644
index 0000000..ab79fd9
--- /dev/null
+++ b/c6.cpp
@@ -0,0 +1,50 @@
+#include<bits/stdc++.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 998244353
+using namespace std;
+ll func(ll mid);
+ll n;
+char str[100005];
+int main()
+{
+	cin>>n;
+	scanf("%s",str);
+	ll low=0,high=0,mid,ans=0;	
+	rep(i,0,n)
+	if(str[i]=='G')
+		high++;
+	//high--;
+	while(low<=high)
+	{
+		mid=(low+high)/2;
+		if(func(mid)==1)
+		{
+			low=mid+1;
+			ans=mid;
+		}
+		else
+			high=mid-1;
+	}
+	printf("%lld",ans);
+}
+ll func(ll mid)
+{
+	ll cnt=0;
+	rep(i,0,mid)
+	if(str[i]=='G')
+		cnt++;
+	if(cnt>=mid-1)
+		return 1;
+
+	rep(i,mid,n)
+	{
+		if(str[i-mid]=='G')
+			cnt--;
+		if(str[i]=='G')
+			cnt++;
+		if(cnt>=mid-1)
+			return 1;
+	}
+	return 0;
+}
\ No newline at end of file
diff --git a/c7.cpp b/c7.cpp
new file mode 100644
index 0000000..2fe0834
--- /dev/null
+++ b/c7.cpp
@@ -0,0 +1,26 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 998244353
+using namespace std;
+ll mem[2005][2005],n,m,k;
+ll func(ll,ll);
+int main()
+{
+	cin>>n>>m>>k;
+	memset(mem,-1,sizeof(mem));
+	printf("%lld",m*func(1,k)%MOD);
+}
+ll func(ll idx,ll k)
+{
+	if(idx==n&&k==0)
+		return 1;
+	if(idx==n)
+		return 0;
+	if(k<0)
+		return 0;
+	if(mem[idx][k]!=-1)
+		return mem[idx][k];
+	return mem[idx][k]=((func(idx+1,k-1)*(m-1))%MOD+func(idx+1,k)%MOD)%MOD;
+}
\ No newline at end of file
diff --git a/chn.cpp b/chn.cpp
new file mode 100644
index 0000000..a2cca21
--- /dev/null
+++ b/chn.cpp
@@ -0,0 +1,48 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+ll hun,fif;
+int main()
+{
+	ll n,flag=0,x;
+	cin>>n;
+	while(n--)
+	{
+		cin>>x;
+		if(x==50)
+			fif++;
+		if(x==100)
+		{
+			if(fif<=0)
+				flag=1;
+			fif--;
+			hun++;
+		}
+		if(x==200)
+		{
+
+			if(hun>0)
+			{
+				if(fif<=0)
+					flag=1;				
+				hun--;
+				fif--;
+			}
+			else
+			{
+				if(fif<3)
+					flag=1;
+				fif-=3;
+			}
+		}
+	}
+	if(flag==0)
+		cout<<"YES";
+	else
+		cout<<"NO";
+}
\ No newline at end of file
diff --git a/cho.cpp b/cho.cpp
new file mode 100644
index 0000000..24163eb
--- /dev/null
+++ b/cho.cpp
@@ -0,0 +1,78 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+using namespace std;
+ll l[55],x,ar[100005];
+ll func(ll);
+ll n,m,t;
+int main()
+{
+ 
+	cin>>t;
+	ll ans=0;
+	while(t--)
+	{
+		ans=0;
+		rep(i,0,52)
+		l[i]=0;
+		cin>>n>>m;
+		rep(i,0,n)
+		{
+			char c;
+			scanf("  %c",&c);
+			ar[i]=c;
+			if(ar[i]<90)
+				ar[i]-=65;
+			else
+				ar[i]=ar[i]-97+26;
+		}
+		ll mid,low=0,high=n;
+		while(low<=high)
+		{
+			mid=(low+high)/2;
+			if(func(mid)==1)
+			{
+				low=mid+1;
+				ans=mid;
+			}
+			else
+				high=mid-1;
+		}
+		//rep(i,0,6)
+		//cout<<l[i]<<" ";
+		cout<<ans<<"\n";
+	}
+}
+ll func(ll mid)
+{
+	ll flag=0,max=0;
+	
+	rep(i,0,52)
+	l[i]=0;		
+	
+	rep(i,0,mid)
+	l[ar[i]]++;
+	
+	rep(i,0,52)
+	if(l[i]>max)
+		max=l[i];
+ 
+	if((mid-max)<=m)
+		return 1;
+ 
+	rep(i,mid,n)
+	{
+		l[ar[i-mid]]--;
+		l[ar[i]]++;
+		
+		rep(i,0,52)
+		if(l[i]>max)
+			max=l[i];
+ 
+		if((mid-max)<=m)
+			return 1;		
+	}
+	return 0;
+}
\ No newline at end of file
diff --git a/cod.cpp b/cod.cpp
new file mode 100644
index 0000000..73458da
--- /dev/null
+++ b/cod.cpp
@@ -0,0 +1,224 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll t;
+    cin>>t;
+    while(t--)
+    {
+        ll n,k;
+        cin>>n>>k;
+        ll a[n];
+        ll i;
+        for(i=0;i<n;i++)
+        {
+            cin>>a[i];
+        }
+        if(n==1)
+        {   
+            if(a[0]>k)
+                cout<<"NO\n";
+            else
+            {
+                cout<<"YES\n";
+                if(a[0]==-1)
+                    cout<<1<<"\n";
+                else
+                    cout<<a[0]<<"\n";
+            }
+        }
+        else
+        {
+        for(i=0;i<n;i++)
+        {
+            if(i==0)
+            {
+                if(a[i]==-1)
+                {
+                    if(a[i+1]==-1)
+                    {
+                        a[i] = 1;
+                    }
+                    else
+                    {
+                        if(a[i+1]==1)
+                            a[i] = a[i+1]+1;
+                        else
+                            a[i] = a[i+1]-1;
+                    }
+                }
+            }
+            else if(i==n-1)
+            {
+                if(a[i]==-1)
+                {
+                    if(a[i-1]==-1)
+                    {
+                        a[i] = 1;
+                    }
+                    else
+                    {
+                        if(a[i-1]==k)
+                            a[i] = a[i-1]-1;
+                        else
+                            a[i] = a[i-1]+1;
+                    }
+                }
+            }
+            else
+            {
+                if(a[i]==-1)
+                {
+                    if(a[i-1]==-1&&a[i+1]==-1)
+                    {
+                        a[i] = 1;
+                    }
+                    else if(a[i-1]==-1&&a[i+1]!=-1)
+                    {
+                        if(a[i+1]==k)
+                        {
+                            a[i] = k-1;
+                        }
+                        else
+                        {
+                            a[i] = a[i+1]+1;
+                        }
+                    }
+                    else if(a[i-1]!=-1&&a[i+1]==-1)
+                    {
+                        if(a[i-1]==k)
+                        {
+                            a[i] = k-1;
+                        }
+                        else
+                        {
+                            a[i] = a[i-1]+1;
+                        }
+                    }
+                    else
+                    {
+                        if(a[i-1]==a[i+1])
+                        {
+                            if(a[i-1]==k)
+                            {
+                                a[i] = k-1;
+                            }
+                            else
+                            {
+                                a[i] = a[i-1]+1;
+                            }
+                        }
+                        else
+                        {
+                            if(a[i-1]==k)
+                            {
+                                if(a[i+1]==k-1)
+                                {
+                                    a[i] = k-2;
+                                }
+                                else
+                                {
+                                    a[i] = k-1;
+                                }
+                            }
+                            else
+                            {
+                                if(a[i+1]==a[i-1]+1)
+                                {
+                                    if(a[i-1]+2>k)
+                                    {
+                                        a[i] = a[i-1]-1;
+                                    }
+                                    else
+                                    {
+                                        a[i] = a[i-1]+2;
+                                    }
+                                }
+                                else
+                                {
+                                    a[i] = a[i-1]+1;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        ll flag = 0;
+        for(i=0;i<n;i++)
+        {
+            if(a[i]>k||a[i]<1)
+            {
+                flag = 1;
+                break;
+            }
+            else
+            {
+                if(i==0)
+                {
+                    if(a[i]==a[i+1])
+                    {
+                        flag = 1;
+                        break;
+                    }
+                }
+                else if(i==n-1)
+                {
+                    if(a[i]==a[i-1])
+                    {
+                        flag = 1;
+                        break;
+                    }
+                }
+                else
+                {
+                    if(a[i]==a[i-1]||a[i]==a[i+1])
+                    {
+                        flag = 1;
+                        break;
+                    }
+                }
+            }
+        }
+        if(flag==1)
+        {
+            cout<<"NO\n";
+        }
+        else
+        {
+            cout<<"YES\n";
+            for(i=0;i<n;i++)
+            {
+                cout<<a[i]<<" ";
+            }
+            cout<<"\n";
+        }
+        }
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/codeforces b/codeforces
new file mode 100644
index 0000000..2760159
Binary files /dev/null and b/codeforces differ
diff --git a/codeforces.cpp b/codeforces.cpp
new file mode 100644
index 0000000..5ef2617
--- /dev/null
+++ b/codeforces.cpp
@@ -0,0 +1,87 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+long long int primeFactors(long long int n)
+{
+    // Print the number of 2s that divide n
+    map<long long int ,long long int > mp;
+    while (n % 2 == 0)
+    {
+        //cout << 2 << " ";
+        mp[2]++;
+        n = n/2;
+    }
+
+    // n must be odd at this point. So we can skip
+    // one element (Note i = i +2)
+    for (int i = 3; i <= sqrt(n); i = i + 2)
+    {
+        // While i divides n, print i and divide n
+        while (n % i == 0)
+        {
+            //cout << i << " ";
+            mp[i]++;
+            n = n/i;
+        }
+    }
+
+    // This condition is to handle the case when n
+    // is a prime number greater than 2
+    if (n > 2)
+        mp[n]++;
+
+      long long int factor=1;
+    map<long long int ,long long int >::iterator it;
+       for(it=mp.begin();it!=mp.end();it++)
+       {
+            factor*=((*it).second+1);
+       }
+       return factor;
+}
+
+int main()
+{
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        long long int n;
+        cin>>n;
+        long long int a[n];
+        map<long long int,long long int> mp;
+        set<long long int> st;
+        for(int i=0;i<n;i++)
+        {
+            cin>>a[i];
+            st.insert(a[i]);
+
+        }
+        sort(a,a+n);
+        int i=0;
+        int j=n-1;
+        long long int flag=0;
+        long long int temp=a[i]*a[j];
+        while(i<j)
+        {
+            if(temp!=(a[i]*a[j]))
+            flag=1;
+            i++;j--;
+        }
+        if(i==j&&(a[i]*a[j])!=temp)
+        flag=1;
+
+        if(flag==1)
+        cout<<"-1\n";
+        else
+        {
+            long long int sto;
+            if((primeFactors(temp))==(st.size()+2))
+            cout<<temp<<"\n";
+            else
+            cout<<"-1\n";
+            }
+
+
+    }
+}
diff --git a/codeforces.o b/codeforces.o
new file mode 100644
index 0000000..a186a91
Binary files /dev/null and b/codeforces.o differ
diff --git a/contributors.md b/contributors.md
new file mode 100644
index 0000000..c0aa2c5
--- /dev/null
+++ b/contributors.md
@@ -0,0 +1,2 @@
+Varun Sharma
+Excel Blaze
diff --git a/cop.cpp b/cop.cpp
new file mode 100644
index 0000000..d9b4296
--- /dev/null
+++ b/cop.cpp
@@ -0,0 +1,62 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll t;
+    cin>>t;
+    ll n,m;
+    cin>>n>>m;
+    ll a[n][m],ans[n*m+1] = {0};
+    ll i,j;
+    for(i=1;i<=n*m;i++)
+    {
+        for(j=0;j<n*m;j+=i)
+        {
+            if(a[j/m][j%m]!=i)
+                ans[i]++;
+            a[j/m][j%m] = i;
+            if(a[j%n][j/n]!=i)
+                ans[i]++;
+            a[j%n][j/n] = i;
+        }
+    }
+    for(i=1;i<=n*m;i++)
+    {
+        cout<<ans[i]<<" ";
+        ans[i] = 0;
+    }
+    cout<<"\n";
+    for(i=0;i<n;i++)
+    {
+        for(j=0;j<m;j++)
+        {
+            a[i][j] = 0;
+        }
+    }  
+    return 0;
+}
\ No newline at end of file
diff --git a/dc b/dc
new file mode 100644
index 0000000..c2e0974
Binary files /dev/null and b/dc differ
diff --git a/evins.txt b/evins.txt
new file mode 100644
index 0000000..90c7c77
--- /dev/null
+++ b/evins.txt
@@ -0,0 +1 @@
+I am here
diff --git a/hack36.cpp b/hack36.cpp
new file mode 100644
index 0000000..5c946d1
--- /dev/null
+++ b/hack36.cpp
@@ -0,0 +1,87 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll n;
+    cin>>n;
+    ll a[n],i;
+    for(i=0;i<n;i++)
+        cin>>a[i];
+    sort(a,a+n);
+    ll prev = -1;
+    ll mn1 = inf,mn2 = inf;
+    ll c1 = 0,c2 = 0;
+    for(i=0;i<n;i++)
+    {
+        if(a[i]%2==0)
+        {   
+            if(c2!=0)
+                mn2 = min(mn2,c2);
+            if(a[i]==prev)
+            {
+                c1++;
+            }
+            else
+            {   
+                if(c1!=0)
+                {  
+                   mn1 = min(mn1,c1);
+                }
+                c1 = 1;
+            }
+        }
+        else
+        {   
+            if(c1!=0)
+                mn1 = min(mn1,c1);
+            if(a[i]==prev)
+            {
+                c2++;
+            }
+            else
+            {   
+                if(c2!=0)
+                {
+                    mn2 = min(mn2,c2);
+                }
+                c2 = 1;
+            }
+        }
+        prev = a[i];
+    }
+    if(c1!=0)
+    {
+        mn1 = min(mn1,c1);
+    }
+    if(c2!=0)
+    {
+        mn2 = min(mn2,c2);
+    }
+    cout<<min(mn1,mn2);
+    return 0;
+}
\ No newline at end of file
diff --git a/hack_in_the_north.cpp b/hack_in_the_north.cpp
new file mode 100644
index 0000000..5c946d1
--- /dev/null
+++ b/hack_in_the_north.cpp
@@ -0,0 +1,87 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll n;
+    cin>>n;
+    ll a[n],i;
+    for(i=0;i<n;i++)
+        cin>>a[i];
+    sort(a,a+n);
+    ll prev = -1;
+    ll mn1 = inf,mn2 = inf;
+    ll c1 = 0,c2 = 0;
+    for(i=0;i<n;i++)
+    {
+        if(a[i]%2==0)
+        {   
+            if(c2!=0)
+                mn2 = min(mn2,c2);
+            if(a[i]==prev)
+            {
+                c1++;
+            }
+            else
+            {   
+                if(c1!=0)
+                {  
+                   mn1 = min(mn1,c1);
+                }
+                c1 = 1;
+            }
+        }
+        else
+        {   
+            if(c1!=0)
+                mn1 = min(mn1,c1);
+            if(a[i]==prev)
+            {
+                c2++;
+            }
+            else
+            {   
+                if(c2!=0)
+                {
+                    mn2 = min(mn2,c2);
+                }
+                c2 = 1;
+            }
+        }
+        prev = a[i];
+    }
+    if(c1!=0)
+    {
+        mn1 = min(mn1,c1);
+    }
+    if(c2!=0)
+    {
+        mn2 = min(mn2,c2);
+    }
+    cout<<min(mn1,mn2);
+    return 0;
+}
\ No newline at end of file
diff --git a/hackercup1.cpp b/hackercup1.cpp
new file mode 100644
index 0000000..a7418b3
--- /dev/null
+++ b/hackercup1.cpp
@@ -0,0 +1,173 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int parent[51];
+int visited[51];
+
+vector<pair<int,int> > adj[51];
+
+
+
+#define INF 10000000000000009
+#define MAX 100009
+#define pii pair <long long ,long long >
+#define pb push_back
+//vector < pii > graph[MAX];
+long long dist[51];
+void Reset()
+{
+	memset(dist,INF,sizeof(dist));
+	long long i;
+	for(i=0;i<MAX;i++)
+	adj[i].clear();
+}
+void dijkstra(long long start)
+{
+	priority_queue < pii , vector< pii >,greater< pii > > q;	//in the priority queue the greater func is default
+ 	dist[start]=0;
+ 	q.push(pii(0,start));	//pushing the starting node
+ 	long long i,v,w,u,c;
+
+ 	while(!q.empty())
+ 	{
+ 		u=q.top().second;
+ 		c=q.top().first;
+ 		q.pop();
+ 		for(i=0;i<adj[u].size();i++)
+ 		{
+
+ 			v=adj[u][i].first;
+ 			w=adj[u][i].second;
+
+ 			if(dist[v]>dist[u]+w)
+ 			{
+ 				dist[v]=dist[u]+w;
+ 				q.push(pii(dist[v],v));
+	 		}
+	    }
+	}
+}
+
+
+
+
+
+int f_parent(int x)
+{
+    if(parent[x]==x)
+    return x;
+
+    parent[x]=f_parent(parent[x]);
+}
+
+
+
+int main()
+{
+    int t;
+    cin>>t;
+
+    while(t--)
+    {
+        int n,m;
+        cin>>n>>m;
+
+        for(int i=1;i<=n;i++)
+        {
+            parent[i]=i;
+        }
+
+        for(int i=0;i<51;i++)
+        adj[i].clear();
+
+
+        vector<pair<int,pair<int,int> > > v;
+
+        int flag=0;
+
+        int x,y,z;
+
+        for(int i=0;i<m;i++)
+        {
+            cin>>x>>y>>z;
+
+            v.push_back(make_pair(z,make_pair(x,y)));
+        }
+
+        sort(v.begin(),v.end());
+
+
+        for(int i=0;i<v.size();i++)
+        {
+            int x1=(v[i].second).first;
+            int y1=(v[i].second).second;
+            int z1=v[i].first;
+
+            if(f_parent(x1)==f_parent(y1))
+            {
+                for(int k=0;k<=51;k++)
+                visited[k]=0;
+                Reset();
+                dijkstra(x1);
+                int d=dist[y1];
+                if(d<z1)
+                {
+                    flag=1;
+                    break;
+                }
+                else if(d>z)
+                {
+                    adj[x1].push_back(make_pair(y1,z1));
+                    adj[y1].push_back(make_pair(x1,z1));
+
+
+                }
+            }
+            else
+            {
+                if(f_parent(x1)<f_parent(y1))
+                {
+                    parent[f_parent(x1)]=parent[f_parent(y1)];
+                }
+                else
+                {
+                    parent[f_parent(y1)]=parent[f_parent(x1)];
+                }
+
+                adj[x1].push_back(make_pair(y1,z1));
+                adj[y1].push_back(make_pair(x1,z1));
+            }
+
+            if(flag==1)
+            cout<<"impossible\n";
+            else
+            {
+                int B[n+1][n+1];
+                memset(B,-1,sizeof(B));
+                int e=0;
+                for(int i=0;i<51;i++)
+                {
+                    for(int j=0;j<adj[i].size();j++)
+                    {
+                        B[i][adj[i][j].first]=adj[i][j].second;
+                        e++;
+                    }
+                }
+
+                cout<<e/2<<"\n";
+                for(int i=1;i<=n;i++)
+                {
+                    for(int j=i+1;j<=n;j++)
+                    {
+                        if(B[i][j]!=-1)
+                        {
+                            cout<<i<<" "<<j<<" "<<B[i][j]<<"\n";
+                        }
+
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/hackercupround22.cpp b/hackercupround22.cpp
new file mode 100644
index 0000000..9bb1114
--- /dev/null
+++ b/hackercupround22.cpp
@@ -0,0 +1,64 @@
+#include<bits/stdc++.h>
+#define mod 1000000007
+using namespace std;
+
+long long int power(long long int a,long long int n)
+{
+    long long int ans=1;
+
+    while(n)
+    {
+        if(n%2==1)
+        {
+            ans=(ans%mod*a%mod)%mod;
+        }
+
+        n=n/2;
+
+        a=(a%mod*a%mod)%mod;
+    }
+
+    return ans;
+}
+
+int main()
+{
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        long long int n,k;
+        cin>>n>>k;
+
+        string str;
+        cin>>str;
+
+        long long int acount=0;
+        long long int bcount=0;
+        long long int ans=0;
+        for(long long int i=0;i<str.length();i++)
+        {
+            if(str[i]=='A')
+            acount++;
+            else
+            bcount++;
+
+            if(acount>=bcount)
+            {
+                acount=0;
+                bcount=0;
+            }
+            else if(bcount-acount>k)
+            {
+                str[i]='A';
+                bcount--;
+                acount++;
+
+                ans=(ans%mod+power(2,i+1)%mod)%mod;
+
+            }
+        }
+
+        cout<<ans<<"\n";
+    }
+}
diff --git a/jms.cpp b/jms.cpp
new file mode 100644
index 0000000..46111ed
--- /dev/null
+++ b/jms.cpp
@@ -0,0 +1,44 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int n,m,k;
+    cin>>n>>m>>k;
+    int aa[n+1][n+1];
+    memset(aa,sizeof(aa),0);
+    while(m--)
+    {
+        int a,b;
+        cin>>a>>b;
+        aa[a][b]=1;
+        aa[b][a]=1;
+
+    }
+    int c,d,k,sum=0,flag=0;
+     for (c = 1; c < n+1; c++) {
+      for (d = 1; d < n+1; d++) {
+        for (k = 1; k < n+1; k++) {
+          sum = sum + aa[c][k]*aa[k][d];
+
+
+        }
+
+        if(sum>=k&&c!=d)
+          {
+          flag=1;
+          break;
+          }
+        aa[c][d] = sum;
+        sum = 0;
+      }
+      if(flag==1)
+          break;
+    }
+
+    if(flag==1)
+    cout<<"YES\n";
+    else
+    cout<<"NO\n";
+}
diff --git a/lazy_with _dp.cpp b/lazy_with _dp.cpp
new file mode 100644
index 0000000..ae0eccd
--- /dev/null
+++ b/lazy_with _dp.cpp	
@@ -0,0 +1,57 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+
+
+
+int main()
+{
+	ll t;
+	cin>>t;
+	ll i,j;
+	for(i=1;i<=t;i++)
+	{
+		string s;
+		cin>>s;
+		ll n = s.length();
+		ll req = ceil((double)(n-1)/(double)(2));
+		ll count1 = 0;
+		for(j=1;j<n;j++)
+		{
+			if(s[j]=='B')
+				count1++;
+		}
+		if(count1<req||count1==(n-1))
+		{
+			cout<<"Case #"<<i<<": N"<<"\n";
+		}
+		else
+		{
+			cout<<"Case #"<<i<<": Y"<<"\n";
+		}
+	}
+}
\ No newline at end of file
diff --git a/ncr.cpp b/ncr.cpp
new file mode 100644
index 0000000..b2c5f6b
--- /dev/null
+++ b/ncr.cpp
@@ -0,0 +1,62 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+int main()
+{
+	ll t,odd[1005],even[1005],n,x,zero,two[63];
+	two[0]=0;
+	rep(i,1,63)
+	two[i]=(two[i-1]+1)+two[i-1];
+	//cout<<two[60];
+
+	cin>>t;
+	while(t--)
+	{
+		zero=1;
+		cin>>n;
+		ll even=0,odd=0;
+		ll make_even=two[62],make_odd=two[62];
+		rep(i,0,n)
+		{
+			cin>>x;
+			if(x%2==0)
+			{
+				even++;
+				if(x!=0)
+					make_odd=1;
+			}	
+			else
+			{
+				odd++;
+				if(x!=1)
+				{
+					rep(i,1,63)
+					{
+						if((x-(x/(two[i]+1))*(two[i]+1)+1<(two[i]+1))&&(two[i]<x))
+						{
+							ll ans=x-(x/(two[i]+1))*(two[i]+1)+1;
+							make_even=MIN(ans,make_even);
+							break;
+						}	
+					}
+
+				}
+			}	
+		}
+		//cout<<make_even<<" ";
+		if((even+odd)%2==0)
+			cout<<"0\n";
+		else
+		{
+			if((make_even==two[62])&&(make_odd==two[62]))
+				cout<<"-1\n";
+			else
+				printf("%lld\n",(make_even>make_odd?make_odd:make_even));
+		}
+	}
+}
\ No newline at end of file
diff --git a/nfa.cpp b/nfa.cpp
new file mode 100644
index 0000000..366aea8
--- /dev/null
+++ b/nfa.cpp
@@ -0,0 +1,50 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+#define fi first
+#define se second
+using namespace std;
+#define mp make_pair
+#define piii pair <pair <ll,ll>,pair <ll,ll>>
+ll sie[1000005][12],ar[1000005];
+void pre();
+int main()
+{
+	pre();
+	ll t,l,r,n;
+	cin>>t;
+	while(t--)
+	{
+		cin>>l>>r>>n;
+		cout<<sie[r][n]-sie[l-1][n]<<"\n";
+	}
+}
+void pre()
+{
+	rep(i,2,1000002)
+	{
+		if(ar[i]==0)
+		{
+			for(int j=i;j<1000005;j+=i)
+			{
+				ar[j]++;
+			}
+		}
+	}
+	//cout<<"GHG";
+	sie[1][0]++;
+	rep(i,2,1000002)
+	{
+		rep(j,0,11)
+		{
+			if(ar[i]==j)
+				sie[i][j]+=sie[i-1][j]+1;
+			else
+				sie[i][j]=sie[i-1][j];
+		}
+	}		
+}
\ No newline at end of file
diff --git a/nicarray.cpp b/nicarray.cpp
new file mode 100644
index 0000000..1df875c
--- /dev/null
+++ b/nicarray.cpp
@@ -0,0 +1,73 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+using namespace std;
+ll func(ll,ll,ll,ll);
+ll GCD(ll,ll);
+ll inv[55],fact[55],n,r; //n total no. of '-1', r remaining sum to be full filled
+int main()
+{
+	fact[0]=1;
+	rep(i,1,52)
+	{
+		fact[i]=(i*fact[i-1])%MOD;
+		inv[i]=i;
+	}	
+	ll t;
+	cin>>t;
+	while(t--)
+	{
+		ll s,sum=0,t,ar[55];
+		n=0;
+		cin>>t>>s;
+		rep(i,0,t)
+		{
+			cin>>ar[i];
+			if(ar[i]==-1)
+				n++;
+			else
+				sum+=ar[i];
+		}
+		s-=sum;
+		ll ans=1;
+		rep(i,0,s-n+1)
+		{
+			ans+=func(1,i,1,r-i);
+		}
+		cout<<ans<<"\n";
+	}
+
+}
+/*ll inverse_(ll n)
+{
+
+}*/
+ll GCD(ll a,ll b)
+{
+	if(b==0)
+		return a;
+	else
+		return GCD(b,a%b);
+}
+ll func(ll idx,ll prev,ll cnt,ll r)
+{
+	if(r<0)
+		return 0;
+	if(idx==n)
+		{
+			cout<<"\n";
+			return inv[cnt];
+		}	
+	ll ans=0,mul;
+	if(r-prev<=r-(n-idx)+1)
+	ans+=func(idx+1,prev,cnt+1,r-prev);
+
+	rep(i,prev+1,r-(n-idx)+2)
+	{
+		mul=cnt;
+		ans+=(func(idx+1,i,0,r-i)*inv[cnt])%MOD;
+	}	
+	return ans;
+}
\ No newline at end of file
diff --git a/par.cpp b/par.cpp
new file mode 100644
index 0000000..c39dc9a
--- /dev/null
+++ b/par.cpp
@@ -0,0 +1,85 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+typedef struct NODE
+{
+	ll enm,size_,par;
+}NODE;
+void initialise();
+ll Find(ll);
+void Union(ll,ll);
+void enemy(ll,ll);
+NODE ar[100005];
+ll n,m,x,y;
+int main()
+{
+	cin>>n>>m;
+	initialise();
+	rep(i,0,m)
+	{
+		cin>>x>>y;
+		Union(x,y);
+	}
+	cin>>m;
+	rep(i,0,m)
+	{
+		cin>>x>>y;
+		enemy(x,y);
+	}
+	ll max_=0;
+	rep(i,1,n+1)
+	{
+		if(ar[i].par==i&&max_<ar[i].size_&&ar[i].enm==0)
+			max_=ar[i].size_;
+	}
+	// rep(i,1,n+1)
+	// {
+	// 	cout<<ar[i].par<<" "<<ar[i].size_<<" "<<ar[i].enm<<"\n";
+	// }
+	cout<<max_;
+}
+void initialise()
+{
+	rep(i,0,n+1)
+	{
+		ar[i].par=i;
+		ar[i].size_=1;
+	}
+}
+ll Find(ll idx)
+{
+	if(ar[idx].par==idx)
+		return idx;
+	return ar[idx].par=Find(ar[idx].par);
+}
+void Union(ll x,ll y)
+{
+	ll px=Find(x);
+	ll py=Find(y);
+	if(px==py)
+		return;
+	if(ar[px].size_>ar[py].size_)
+	{
+		ar[py].par=px;
+		ar[px].size_+=ar[py].size_;
+	}
+	if(ar[px].size_<=ar[py].size_)
+	{
+		ar[px].par=py;
+		ar[py].size_+=ar[px].size_;
+	}
+}
+void enemy(ll a,ll b)
+{
+	ll pa=Find(a);
+	ll pb=Find(b);
+	if(pa==pb)
+	{
+		ar[pa].enm=1;
+	}
+}
\ No newline at end of file
diff --git a/pat.cpp b/pat.cpp
new file mode 100644
index 0000000..0630bf1
--- /dev/null
+++ b/pat.cpp
@@ -0,0 +1,143 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 163577857
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+ll ar[75][75],n,q,t;
+void rev_();
+void func1();
+void func2(char,ll,ll);
+int main()
+{
+	func2('C',0,0);
+	cin>>t;
+	while(t--)
+	{
+		cin>>q>>n;
+		if(q==2)
+		{
+			func1();
+			rep(i,0,n)
+			{
+				rep(j,0,n)
+				cout<<ar[i][j]<<" ";
+				cout<<"\n";
+			}
+		}
+		if(q==1)
+		{
+			func2('C',0,0);
+			if(n%2==1)
+				ar[n/2][n/2]=n*n;
+			rep(i,0,n)
+			{
+				rep(j,0,n)
+				cout<<ar[i][j]<<" ";
+				cout<<"\n";
+			}			
+		}
+	}
+}
+void func1()
+{
+	ll t=0,b=n-1;
+	ll tot=1,j;
+	rep(k,0,n)
+	{
+		j=0;
+		for(int i=t;i>=0;i--,j++)
+		{
+			ar[j][i]=tot;
+			tot++;
+		}
+		if(tot!=n*n+1)
+		{
+			j=0;
+			for(int i=t;i>=0;i--,j++)
+			{
+				ar[n-i-1][n-j-1]=tot;
+				tot++;
+			}
+			t++;
+		}	
+	}
+}
+void func2(char ch,ll a,ll m)
+{
+	if(a==(n/2))
+		return;
+	if(ch=='C')
+	{
+		ll tot=0;
+		rep(i,a,n-1-a)
+		{
+			ar[a][i]=4*tot+m+1;
+			tot++;
+		}
+		tot=0;
+		rep(i,a,n-1-a)
+		{
+			ar[i][n-1-a]=m+2+4*tot;
+			tot++;
+		}
+		tot=0;
+		for(int i=n-1-a;i>a;i--)
+		{
+			ar[n-1-a][i]=m+3+4*tot;
+			tot++;
+		}			
+		tot=0;
+		for(int i=n-1-a;i>a;i--)
+		{
+			ar[i][a]=m+4+4*tot;
+			tot++;
+		}
+		func2('A',a+1,m+(n-1-2*a)*4);
+	}
+	if(ch=='A')
+	{
+		//cout<<"sfdff ";
+		rev_();
+		ll tot=0;
+		rep(i,a,n-1-a)
+		{
+			ar[i][a]=m+4*tot+1;
+			tot++;
+		}
+		tot=0;
+		rep(i,a,n-1-a)
+		{
+			ar[n-1-a][i]=m+2+4*tot;
+			tot++;
+		}
+		tot=0;
+		for(int i=n-1-a;i>a;i--)
+		{
+			ar[i][n-1-a]=m+3+4*tot;
+			tot++;
+		}			
+		tot=0;
+		for(int i=n-1-a;i>a;i--)
+		{
+			ar[a][i]=m+4+4*tot;
+			tot++;
+		}
+		rev_();
+		func2('C',a+1,m+(n-1-2*a)*4);
+	}
+}
+void rev_()
+{
+	rep(i,0,n)
+	{
+		rep(j,0,n)
+		{
+			ll temp=ar[i][j];
+			ar[i][j]=ar[j][i];
+			ar[j][i]=temp;
+		}
+	}		
+}
\ No newline at end of file
diff --git a/pic.cpp b/pic.cpp
new file mode 100644
index 0000000..411358a
--- /dev/null
+++ b/pic.cpp
@@ -0,0 +1,40 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+using namespace std;
+#define INF 0x3f3f3f3f3f3f3LL
+#define MAX(a,b) (a>b?a:b)
+ll mem[202][202][202];
+ll n,k,x,ar[205];
+ll func(ll,ll,ll);
+int main()
+{
+	rep(i,0,200)
+	rep(j,0,200)
+	rep(k,0,200)
+	mem[i][j][k]=-1;
+
+	cin>>n>>k>>x;
+	rep(i,0,n)
+	cin>>ar[i];
+	printf("%lld",func(0,0,1)>0?func(0,0,1):-1);
+
+
+}
+ll func(ll idx,ll used,ll prev)
+{
+	if(used>x)
+		return -1*INF;	
+	if(idx==n)
+		return 0;
+	
+	if(mem[idx][used][prev]!=-1)
+		return mem[idx][used][prev];
+
+	if(prev==k)
+		return mem[idx][used][prev]=func(idx+1,used+1,1)+ar[idx];
+
+	return mem[idx][used][prev]=MAX(func(idx+1,used+1,1)+ar[idx],func(idx+1,used,prev+1));
+}
\ No newline at end of file
diff --git a/pl2.cpp b/pl2.cpp
new file mode 100644
index 0000000..5443a9c
--- /dev/null
+++ b/pl2.cpp
@@ -0,0 +1,53 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+using namespace std;
+char grid[1000][1000],ar[1005];
+ll check(ll,ll);
+ll n;
+int main()
+{
+	cin>>n;
+	rep(i,0,n)
+	rep(j,0,n)
+	scanf(" %c",&grid[i][j]);
+	ll cnt=0,max=0;
+	for(int i=0;i<n;i++)
+	{
+		if(ar[i]!=-1)
+		for(int j=0;j<n;j++)
+		{
+			if(grid[i][j]=='T')
+			{
+
+				if(i!=j&&check(i,j)==1)
+				{
+					cnt=0;
+					break;
+				}	
+				else
+				{
+					cnt++;
+					ar[j]=-1;
+				}	
+				//cout<<j<<" "<<cnt<<"\n";
+			}
+		}	
+		if(cnt>max)
+		{
+			max=cnt;
+			cnt=0;
+		}		
+	}
+	printf("%lld",max);
+
+}
+ll check(ll i,ll j)
+{
+	rep(k,0,n)
+	if(grid[i][k]!=grid[j][k])
+		return 1;
+	return 0;
+}
\ No newline at end of file
diff --git a/tech_code.cpp b/tech_code.cpp
new file mode 100644
index 0000000..61f2fab
--- /dev/null
+++ b/tech_code.cpp
@@ -0,0 +1,51 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{   
+    ll t;
+    cin>>t;
+    while(t--)
+    {
+        ll a,b,n;
+        cin>>a>>b>>n;
+        if(n%3==0)
+        {
+            cout<<a<<"\n";
+        }
+        else if(n%3==1)
+        {
+            cout<<b<<"\n";
+        }
+        else
+        {   
+            ll c = a^b;
+            cout<<c<<"\n";
+        }
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/techkriti.cpp b/techkriti.cpp
new file mode 100644
index 0000000..f46ea2f
--- /dev/null
+++ b/techkriti.cpp
@@ -0,0 +1,69 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod                   1000000007
+#define ll                    long long
+#define Author                std::ios_base::sync_with_stdio(0);
+#define NIKHIL_SETHI          cout.tie(0);
+#define MNNIT_ALLAHABAD       cin.tie(0);
+#define umii                  unordered_map<ll,ll>
+#define mii                   map<ll,ll>
+#define pii                   pair<ll,ll>
+#define all(v)                v.begin(),v.end()
+#define forP(i,j,k)           for(i=j; i<k; i++)
+#define forN(i,j,k)           for(i=j; i>k; i--)
+#define pb(a)                 push_back(a)
+#define lb(v,t)               lower_bound(all(v),t)-v.begin()
+#define ub(v,t)               upper_bound(all(v),t)-v.begin()
+#define inf 1e18
+ 
+//mainly used functions
+bool prime[10000001];
+ll abst(ll a){if(a<0)return -a; return a;}
+ll power(ll a, ll b){ll res=1;while(b){if(b&1)res=res*a;a=a*a;b/=2;}return res;}
+ll invmod(ll a){return power(a,mod-2);}
+ll lcm(ll a, ll b){return a*b/__gcd(a,b);}
+ll ncr(ll n, ll r){ll p=1;ll i;for(i=1; i<=r; i++){p*=(n-i+1);p*=i;}return p;}
+void sieve(){ll i;ll j;memset(prime,true,10000000);prime[0]=prime[1]=false;for(i=2; i*i<=10000000; i++){if(prime[i]){for(j=2*i; j<=10000000; j+=i){prime[j]=false;}}}}
+
+int main()
+{
+    ll n;
+    cin>>n;
+    ll a[n];
+    ll i,j;
+    for(i=0;i<n;i++)
+        cin>>a[i];
+    unordered_map <ll,ll> m;
+    ll ans = n-1;
+    for(i=0;i<n;i++)
+    {
+        bool vp = true;
+        for(j=0;j<i;j++)
+        {
+            m[a[j]]++;
+            if(m[a[j]]==2)
+            {
+                vp = false;
+                break;
+            }
+        }
+        ll su = n;
+        for(j=n-1;j>=i;j--)
+        {   
+            m[a[j]]++;
+            if(m[a[j]]==1)
+            {
+                su = j;
+            }
+            else
+                break;
+        }
+        if(vp)
+        {
+            ans = min(ans,su-i);
+        }
+        m.clear();
+    }
+    cout<<ans;
+    return 0;
+}
\ No newline at end of file
diff --git a/vessi2.cpp b/vessi2.cpp
new file mode 100644
index 0000000..032f48a
--- /dev/null
+++ b/vessi2.cpp
@@ -0,0 +1,57 @@
+    #include<bits/stdc++.h>
+    #define ll long long int 
+    #define pb push_back
+    using namespace std;
+    const int N=1e5+5;
+     
+    int main()
+    {
+    	ll n;
+    	cin>>n;
+    	ll a[n+5];
+    	ll b[n+5];
+    	ll i;
+    	map<ll,ll>mp;
+    	for(i=1;i<=n;i++){
+    		cin>>a[i];
+    		mp[a[i]]=i;
+    	}
+     
+    	//queue<ll>q;
+     
+    	for(i=1;i<=n;i++){
+    		cin>>b[i];
+    		//q.push(b[i]);
+    	}
+     
+    	ll j=1;
+    	ll ans=0;
+    	//ll cnt=1;
+    	bool visited[1000005]={0};
+    	for(i=1;i<=n && j<=n;i++)
+    	{
+    		//ll cnt=0;
+    		if(visited[a[i]]==true)
+    			continue;
+    		if(j<=n &&a[i]==b[j]){
+    			j++;
+    			continue;
+    		}
+    		else
+    		{
+    			while(j<=n && a[i]!=b[j])
+    			{
+    			
+    				//cnt++;
+    				ans++;
+    				visited[b[j]]=1;
+    				j++;
+    			}
+    			j++;
+    		}
+    		
+    		
+    		//ans+=cnt;
+    	}
+    	cout<<ans<<"\n";
+    }
diff --git a/vessi3.cpp b/vessi3.cpp
new file mode 100644
index 0000000..bf9619a
--- /dev/null
+++ b/vessi3.cpp
@@ -0,0 +1,76 @@
+#include<bits/stdc++.h>
+#define ll long long int
+//#define mp make_pair
+using namespace std;
+ll a[300005];
+ 
+int main()
+{
+	ll t;
+	cin>>t;
+	ll n;
+	while(t--)
+	{
+		cin>>n;
+		string s;
+		cin>>s;
+		ll i,j,k,num;
+		//
+		for(i=0;i<n;i++)
+			a[i]=s[i]-'0';
+		ll ans[n+5]={0};
+		bool flag=true;
+		for(num=0;num<10;num++)
+		{
+			string l="";
+			string r="";
+			char x;
+			for(i=0;i<n;i++)
+			{
+				x=a[i]+'0';
+				if(a[i]<num)
+				{
+					//x=a[i]+'0';
+					l+=x;
+					ans[i]=1;
+				}
+				else if(a[i]==num ) 
+				{
+					//x=a[i]
+					ll var=r.size();
+					if(r.size()==0){
+						r+=x;
+						ans[i]=2;
+					}
+					else if(var>0 && r[var-1]==x){
+						r+=x;
+						ans[i]=2;
+					}
+					else {
+						l+=x;
+						ans[i]=1;
+					}
+				}
+				//else if(a[i]==num &&  r.size()>0 && r[r.size()-1]==x){
+				//	r+=x;
+				//	a[i]=2;
+				//}
+				else if(a[i]>num)
+				{
+					r+=x;
+					ans[i]=2;
+				}
+			}
+			l+=r;
+			if(is_sorted(l.begin(),l.end())){
+				for(k=0;k<n;k++){
+					cout<<ans[k];
+					flag=false;
+				}
+				break;
+			}
+		}
+		if(flag)
+		cout<<"-";
+		cout<<"\n";
+	}
diff --git a/vessi4.cpp b/vessi4.cpp
new file mode 100644
index 0000000..685801d
--- /dev/null
+++ b/vessi4.cpp
@@ -0,0 +1,34 @@
+    #include<bits/stdc++.h>
+    #define ll long long int
+     
+    using namespace std;
+    const int mod=1e8;
+    ll n1,n2,k1,k2;
+    //
+    ll dp[101][101][11][11];
+     
+    ll fun(ll x1,ll x2,ll c1,ll c2)
+    {
+    	ll &ans=dp[x1][x2][c1][c2];
+     
+    	if(x1==0 && x2==0)
+    		return 1;
+     
+    	if(ans!=-1)
+    		return ans;
+    	ans=0;
+    	if(x1>0 && c1<k1)
+    		ans=(ans+fun(x1-1,x2,c1+1,0))%mod;
+    	if(x2>0 && c2<k2)
+    		ans=(ans+fun(x1,x2-1,0,c2+1))%mod;
+    //	cout<<ans<<"\n";
+    	return ans%mod;
+    }
+     
+    int main()
+    {
+    	cin>>n1>>n2>>k1>>k2;
+    	memset(dp,-1,sizeof(dp));
+     
+    	cout<<fun(n1,n2,0,0)<<"\n";
+    }
diff --git a/vessi5.cpp b/vessi5.cpp
new file mode 100644
index 0000000..6d57c7e
--- /dev/null
+++ b/vessi5.cpp
@@ -0,0 +1,33 @@
+    #include<bits/stdc++.h>
+    #define ll long long int
+    using namespace std;
+    const int N=2e5+5;
+    ll dp[N];
+    string s;
+    //basically i am storing the lis from back for a string 
+    //from behind intution is if dp[i]==dp[i+1]+1 your answer will be updated to 0 if its 1;
+     
+    int main()
+    {
+    	cin>>s;
+    	ll i;
+    	ll cnt=0;
+    	memset(dp,0,sizeof(dp));
+    	ll n=s.size();
+    	for(i=n-1;i>=0;i--)
+    	{
+    		if(s[i]=='1'){
+    			cnt++;
+    			dp[i]=max(dp[i+1],cnt);
+    		}
+    		else
+    			dp[i]=dp[i+1]+1;
+    	}
+     
+    	for(i=n-1;i>=0;i--)
+    	{
+    		if(s[i]=='1' && dp[i]==dp[i+1]+1)
+    			s[i]='0';
+    	}
+    	cout<<s<<"\n";
+    }
diff --git a/vessi6.cpp b/vessi6.cpp
new file mode 100644
index 0000000..4008342
--- /dev/null
+++ b/vessi6.cpp
@@ -0,0 +1,52 @@
+    #include<bits/stdc++.h>
+    #define ll long long int 
+    using namespace std;
+    int main()
+    {
+    	ll n;
+    	cin>>n;
+     
+    	ll a[n+5];
+    	ll hsh[150005]={0};
+    	
+    	ll i;
+    	ll maxi=0;
+    	for(i=0;i<n;i++)
+    	{
+    		cin>>a[i];
+    		maxi=max(maxi,a[i]);
+    		//hsh[a[i]]++;
+    	}
+    	ll ans=0;
+    	sort(a,a+n);
+    	for(i=0;i<n;i++)
+    	{
+    		if(a[i]==1)
+    		{
+    			if(hsh[a[i]]==0)
+    			{
+    				ans++;
+    				hsh[a[i]]=1;
+    			}
+    			else if(hsh[a[i]+1]==0)
+    			{
+    				ans++;
+    				hsh[a[i]+1]=1;
+    			}
+    		}
+    		else
+    		{
+    			for(ll j=-1;j<2;j++)
+    			{
+    				if(hsh[a[i]+j]==0)
+    				{
+    					ans++;
+    					hsh[a[i]+j]=1;
+    					break;
+    				}
+    			}
+     
+    		}
+    	}
+    	cout<<ans<<"\n";
+    }
diff --git a/war.cpp b/war.cpp
new file mode 100644
index 0000000..be39da6
--- /dev/null
+++ b/war.cpp
@@ -0,0 +1,95 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+#define pii pair <ll,ll>
+using namespace std;
+#define mp make_pair
+#define fi first
+#define se second
+#define piii pair<double,pair<ll,ll>>
+ll q,a,b,m,ar[100],two[55],size_;
+ll pos();
+ll bin(ll,ll);
+ll c,temp,mul,idx,ext,tot;
+void print_();
+int main()
+{
+	two[0]=1;
+	rep(i,1,55)
+	two[i]=(2*two[i-1]);
+	cin>>q;
+	while(q--)
+	{
+		cin>>a>>b>>m;
+		c=a,temp=a,mul=0;
+		if(!pos())
+		{
+			cout<<"-1\n";
+		}
+		else
+		{
+			print_();
+			rep(i,0,size_)
+				cout<<ar[i]<<" ";
+			cout<<"\n";
+		}
+	}
+}
+
+ll pos()
+{
+	ll flag=0,c=a,temp=a,mul=0;
+	size_=0;
+	for(int i=0;i<=1000;i++)
+	{
+		//cout<<temp<<" "<<mul<<"\n";
+		if(b>=temp+mul&&b<=temp+mul*m)
+		{
+			idx=i+1;
+			ext=b-temp;
+			tot=mul;
+			return 1;
+		}
+		if(b<=temp+mul)
+			return 0;
+		temp=(c*two[i]);
+		mul=two[i];
+	}
+}
+void print_()
+{
+	ll c=a,temp=a,mul=0,b=0;
+	for(int i=0;i<idx;i++)
+	{
+		ar[size_++]=temp+b;
+		temp=c*two[i];
+		b=bin((tot+1)/2,ext);
+		ext-=((tot+1)/2)*b;
+		tot/=2;
+	}	
+}
+ll bin(ll mul,ll tot)
+{
+	ll low=1,high=m,mid,ans;
+	while(low<=high)
+	{
+		mid=(low+high)/2;
+		ll rem=tot-mid*m;
+		if(mul<=rem&&rem<=mul*m)
+		{
+			return mid;
+		}
+		else if(rem<mul)
+		{
+			high=mid-1;
+		}
+		else
+		{
+			low=mid+1;
+		}
+	}
+}
\ No newline at end of file
diff --git a/war1.cpp b/war1.cpp
new file mode 100644
index 0000000..2faba73
--- /dev/null
+++ b/war1.cpp
@@ -0,0 +1,49 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 12345678123456
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define MIN(a,b) (a>b?b:a)
+#define fi first
+#define se second
+using namespace std;
+#define mp make_pair
+#define pii pair <ll,ll>
+#define piii pair <pair <ll,ll>,pair <ll,ll>>
+ll n,ar[300005],ans[300005],tot,size_;
+set <ll> s;
+int main()
+{
+	cin>>n;
+	rep(i,1,n+1)
+	{
+		cin>>ar[i];
+	}
+	s.insert(ar[1]);
+	ans[ar[1]]=1;
+	rep(i,2,n+1)
+	for(auto itr=s.begin();itr!=s.end();itr++)
+	{
+		ll x=*itr;
+		if(ar[i]*x<=300005&&ans[ar[i]*x]==0)
+		{
+			ans[ar[i]*x]=i;
+			s.insert(ar[i]*x);
+		}
+		if(ans[ar[i]]==0)
+		{
+			s.insert(ar[i]);
+			ans[ar[i]]=i;
+		}
+	}
+	rep(i,1,n+1)
+	cout<<ans[ar[i]]<<" ";
+}
\ No newline at end of file
diff --git a/war2.cpp b/war2.cpp
new file mode 100644
index 0000000..7681f0d
--- /dev/null
+++ b/war2.cpp
@@ -0,0 +1,50 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 12345678123456
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define MIN(a,b) (a>b?b:a)
+#define fi first
+#define se second
+using namespace std;
+#define mp make_pair
+#define pii pair <ll,ll>
+#define piii pair <pair <ll,ll>,pair <ll,ll>>
+ll n,ar[300005],c=100005,k,x;
+int main()
+{
+	cin>>n>>k;
+	k+=c;
+	rep(i,0,n)
+	{
+		cin>>x;
+		ar[x+c]=1;
+	}
+	ll ans=0;
+	rep(i,0,300005 )
+	{
+		if(ar[i])
+			ans++;
+	}	
+	ll flag=0,a=-1,b=-1;
+	rep(i,0,k)
+	if(ar[i])
+		a=max(a,(ll)i);
+	rep(i,k+1,300005)
+		if(ar[i]==1)
+		{
+			b=i;
+			break;
+		}
+	if(ar[k]==0&&(k-a)==(b-k))
+		flag=1;
+	cout<<ans-flag;
+}
\ No newline at end of file
diff --git a/wat.cpp b/wat.cpp
new file mode 100644
index 0000000..c03471e
--- /dev/null
+++ b/wat.cpp
@@ -0,0 +1,56 @@
+#include<bits/stdc++.h>
+#include<math.h>
+#define rep(i,k,n) for(int i=k;i<n;i++)
+#define ll long long
+#define MOD 1000000007
+#define INF 0x3f3f3f3f3f3f3f3f
+#define MIN(a,b) (a>b?b:a)
+using namespace std;
+ll func(ll);
+ll t,n,ar[100005],low,high,mid,k,gap,mingap,ans;
+int main()
+{
+	cin>>t;
+	while(t--)
+	{
+		mingap=INF;
+		cin>>n;
+		rep(i,0,n)
+		cin>>ar[i];
+		low=0;
+		high=ar[n-1];
+
+		while(low<=high)
+		{
+			mid=(low+high)/2;
+			gap=INF;
+			if(func(mid)==1)
+			{
+				ans=mid;
+				mingap=gap;
+				low=mid+1;
+			}
+			else
+				high=mid-1;
+		}
+		if(n!=1)
+		cout<<ans<<" "<<mingap+1<<"\n";
+		else
+			cout<<ar[0]-1<<" "<<ar[0]<<"\n";
+
+	}
+}
+ll func(ll mid)
+{
+	ll s=1;
+	rep(i,0,n)
+	{
+		if(ar[i]<s)
+			return 0;
+		if((ar[i]-s)<gap)
+			gap=ar[i]-s;
+
+		s+=mid;
+	}
+	return 1;
+}
\ No newline at end of file
diff --git a/xyx.cpp b/xyx.cpp
new file mode 100644
index 0000000..f876dc6
--- /dev/null
+++ b/xyx.cpp
@@ -0,0 +1,106 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define mod 1000000007
+#define ll long long int
+#define pb push_back
+#define mp make_pair
+#define fi first
+#define se second
+#define boost ios_base::sync_with_stdio(false);cin.tie(NULL);
+#define inf 9223372036854775807
+#define mini 9223372036854775807
+#include <ext/pb_ds/assoc_container.hpp> 
+#include <ext/pb_ds/tree_policy.hpp> 
+using namespace __gnu_pbds; 
+#define ordered_set tree<ll, null_type,less<ll>, rb_tree_tag,tree_order_statistics_node_update>
+pair<ll,ll>s4[4]={{-1,0},{1,0},{0,-1},{0,1}};
+pair<ll,ll>s8[8]={{-1,-1},{-1,0},{-1,1},{0,-1},{0,1},{1,1},{1,0},{1,-1}};
+ll power(ll a,ll b)
+{
+	if(b==0)
+		return 1;
+	ll c=power(a,b/2);
+	if(b%2==0)
+		return ((c%mod)*(c%mod))%mod;
+	else
+		return ((((c%mod)*(c%mod))%mod)*a)%mod;
+}
+ll n;
+char ch[55][55];
+ll dp[55][55][55];
+ll func(ll r1,ll r2,ll c1,ll c2)
+{
+	if(dp[r1][r2][c1][c2]!=-1)
+		return dp[r1][r2][c];
+	if(r1==r2 || c1>=c2)
+		return 0;
+	if(ch[r1][c1]=='.')
+	{
+		//cout<<"-------...............------"<<endl;
+		ll hashed[55];
+		memset(hashed,0,sizeof(hashed));
+		ll ans=mini;
+		ll tr[55];
+		ll lc[55];
+		for(ll xx=0; xx<55; xx++)
+		{
+			tr[xx]=mini;
+			lc[xx]=mini;
+		}
+		for(ll i=r1+1; i<=r2; i++)
+		{
+			for(ll j=c1+1; j<=c2; j++)
+			{
+				if(ch[i-1][j-1]=='#')
+				{
+					ashed[j-1]=1;
+					tr[j-1]=min(tr[j-1],i-1);
+					lc[i-1]=min(lc[i-1],j-1);
+				}
+				if(j-2>=0)
+				{
+					hashed[j-1]=max(hashed[j-2],hashed[j-1]);
+					tr[j-1]=min(tr[j-1],tr[j-2]);
+				}
+				if(i-2>=0)
+					lc[i-1]=min(lc[i-1],lc[i-2]);
+				if(hashed[j-1]>0)
+				{
+					ll hor=i-tr[j-1];
+					ll ver=j-lc[i-1];
+					ll val=max(hor,ver);
+					ans=min(ans,val+min(func(r1,i,j,c2)+func(i,r2,c1,c2),func(r1,r2,j,c2)+func(i,r2,c1,j)));
+				}
+				else
+					ans=min(ans,func(r1,i,j)+func(i,r2,c));
+			}
+		}
+		return dp[r1][r2][c]=ans;
+	}
+	else
+	{
+		ll ans=mini;
+		for(ll i=r1+1; i<=r2; i++)
+		{
+			for(ll j=c+1; j<=n; j++)
+			{
+				ll hor=i-r1;
+				ll ver=j-c;
+				ll val=max(hor,ver);
+				ans=min(ans,val+func(r1,i,j)+func(i,r2,c));
+			}
+		}
+		return dp[r1][r2][c]=ans;
+	}
+}
+int main()
+{
+	boost
+	memset(dp,-1,sizeof(dp));
+	cin>>n;
+	for(ll i=0; i<n; i++)
+		for(ll j=0; j<n; j++)
+			cin>>ch[i][j];
+	cout<<func(0,n,0)<<endl;
+	return 0;
+}
diff --git a/xyz.cpp b/xyz.cpp
new file mode 100644
index 0000000..dde3b5c
--- /dev/null
+++ b/xyz.cpp
@@ -0,0 +1,38 @@
+#include<bits/stdc++.h>
+#define ll long long int 
+#define pb push_back
+#define mp make_pair
+
+using namespace std;
+
+int main()
+{
+	ll n;
+	string s;
+	cin>>n>>s;
+	//
+
+
+	ll i,j;
+	vector<ll>bc;
+	ll ans=n*(n-1)/2;
+
+	for(i=0;i<n;)
+	{
+		j=i;
+
+		while(j<n && s[i]==s[j]){
+			j++;
+		}
+		bc.pb(j-i);
+		i=j;
+	}
+	ll val=0;
+	for(i=0;i<bc.size()-1;i++)
+	{
+		val=val+bc[i]+bc[i+1]-1;
+	//	cout<<bc[i]<<" "<<bc[i+1]<<"\n"
+		//ek jyada minus kar diya usko plus kiya :)
+	}
+	cout<<ans-val<<"\n";
+}