diff --git a/Hackerrank/First.java b/Hackerrank/First.java
new file mode 100644
index 0000000..3c9118b
--- /dev/null
+++ b/Hackerrank/First.java
@@ -0,0 +1,28 @@
+ import java.io.*;
+import java.util.*;
+import java.text.*;
+import java.math.*;
+import java.util.regex.*;
+
+public class Solution {
+//This is a practice problem from hackerrank solve me first
+
+
+    static int solveMeFirst(int a, int b) {
+      // Hint: Type return a+b; below
+      
+	}
+
+ public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        int a;
+        a = in.nextInt();
+        int b;
+        b = in.nextInt();
+        int sum;
+        sum = solveMeFirst(a, b);
+        System.out.println(sum);
+	}
+}
+
+
diff --git a/Hackerrank/Hashmap.java b/Hackerrank/Hashmap.java
new file mode 100644
index 0000000..4b81693
--- /dev/null
+++ b/Hackerrank/Hashmap.java
@@ -0,0 +1,30 @@
+ 
+//Complete this code or write your own from scratch
+import java.util.*;
+import java.io.*;
+
+class Hashmap{
+   public static void main(String []argh)
+   {
+      Scanner x = new Scanner(System.in);
+      int n=x.nextInt();
+      x.nextLine();
+      Map<String, Integer> map = new HashMap<String, Integer>();
+      for(int i=0;i<n;i++)
+      {
+          String name = x.next();
+          int phone = x.nextInt();
+          x.nextLine();
+         map.put(name, phone);
+      }
+      while(x.hasNext())
+      {
+         String s=x.nextLine();
+         if (map.get(s) != null) {
+             System.out.println(s+"="+map.get(s));
+         } else {
+             System.out.println("Not found");
+         }
+      }
+   }
+}
diff --git a/Hackerrank/Review.java b/Hackerrank/Review.java
new file mode 100644
index 0000000..32127eb
--- /dev/null
+++ b/Hackerrank/Review.java
@@ -0,0 +1,35 @@
+ import java.io.*;
+import java.util.*;
+import java.text.*;
+import java.math.*;
+import java.util.regex.*;
+import java.lang.Iterable.*;
+
+public class Review {
+//code to print odd and even numbers separetely
+    public static void main(String[] args) {
+        /*Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
+     Scanner x=new Scanner(System.in);
+     int n=x.nextInt(); 
+     x.nextLine();
+     String strings[]=new String[100] ;
+     for(int i=0;i<n;i++)
+     strings[i]=x.nextLine();       
+     for(int i = 0;i < n;i++){
+        String word = strings[i];
+        ArrayList<Integer> oddIndexes  = new ArrayList<>(100);
+        for(int j= 0; j < word.length();j++){
+            if(j % 2 == 0){
+                System.out.print(word.charAt(j));
+            }else{
+                oddIndexes.add(j);
+            }
+        }
+        System.out.print(" ");
+        for(Integer index : oddIndexes){
+            System.out.print(word.charAt(index));
+        }
+        System.out.println();
+    }
+ }}
+
diff --git a/Hackerrank/Simplearray.java b/Hackerrank/Simplearray.java
new file mode 100644
index 0000000..b5b4897
--- /dev/null
+++ b/Hackerrank/Simplearray.java
@@ -0,0 +1,43 @@
+ 
+import java.io.*;
+import java.math.*;
+import java.text.*;
+import java.util.*;
+import java.util.regex.*;
+
+public class Simplearray {
+
+    /*
+     * Complete the simpleArraySum function below.
+     */
+    static int simpleArraySum(int[] ar) {
+        /*
+         * Write your code here.
+         */
+
+    }
+
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) throws IOException {
+        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
+
+        int arCount = Integer.parseInt(scanner.nextLine().trim());
+
+        int[] ar = new int[arCount];
+
+        String[] arItems = scanner.nextLine().split(" ");
+
+        for (int arItr = 0; arItr < arCount; arItr++) {
+            int arItem = Integer.parseInt(arItems[arItr].trim());
+            ar[arItr] = arItem;
+        }
+
+        int result = simpleArraySum(ar);
+
+        bufferedWriter.write(String.valueOf(result));
+        bufferedWriter.newLine();
+
+        bufferedWriter.close();
+    }
+}