diff --git "a/\355\225\234\352\260\200\354\235\200/10866.py" "b/\355\225\234\352\260\200\354\235\200/10866.py"
new file mode 100644
index 0000000..10d9e95
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/10866.py"
@@ -0,0 +1,24 @@
+from collections import deque
+import sys
+
+n = int(input())
+answer = deque()
+for _ in range(n):
+    a = list(sys.stdin.readline().split())
+    
+    if a[0] == 'push_front':
+        answer.appendleft(a[1])
+    elif a[0] == 'push_back':
+        answer.append(a[1])
+    elif a[0] == 'pop_front':
+        print(answer.popleft() if answer else -1)
+    elif a[0] == 'pop_back':
+        print(answer.pop() if answer else -1)
+    elif a[0] == 'size':
+        print(len(answer))
+    elif a[0] == 'empty':
+        print(0 if answer else 1)
+    elif a[0] == 'front':
+        print(answer[0] if answer else -1)
+    else : # a == 'back'
+        print(answer[-1] if answer else -1)
\ No newline at end of file
diff --git "a/\355\225\234\352\260\200\354\235\200/10989.py" "b/\355\225\234\352\260\200\354\235\200/10989.py"
new file mode 100644
index 0000000..6c6bda6
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/10989.py"
@@ -0,0 +1,13 @@
+import sys
+
+n = int(sys.stdin.readline())
+num_list = [0] * 10001
+
+for _ in range(n):
+    num_list[int(sys.stdin.readline())] += 1
+
+for i in range(10001):
+    if num_list[i] != 0:
+        for j in range(num_list[i]):
+            print(i)
+            
\ No newline at end of file
diff --git "a/\355\225\234\352\260\200\354\235\200/1463.py" "b/\355\225\234\352\260\200\354\235\200/1463.py"
new file mode 100644
index 0000000..6c2c67f
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/1463.py"
@@ -0,0 +1,11 @@
+# 1로 만들기
+def make_one(n):
+    D = [0] *(n+1)
+    for i in range(2, n+1):
+        D[i] = D[i-1] + 1
+        if i % 2 == 0: D[i] = min(D[i], D[i//2] + 1)
+        if i % 3 == 0: D[i] = min(D[i], D[i//3] + 1)
+    return D[n]
+
+n = int(input())
+print(make_one(n))
\ No newline at end of file
diff --git "a/\355\225\234\352\260\200\354\235\200/15649.py" "b/\355\225\234\352\260\200\354\235\200/15649.py"
new file mode 100644
index 0000000..9f8c30b
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/15649.py"
@@ -0,0 +1,18 @@
+def back_tracking(arr, len, used_num):
+    if len == m:
+        print(*arr)
+        return
+    
+    for i in range(1, n+1):
+        if not used_num[i]:
+            arr.append(i)
+            used_num[i] = True
+            back_tracking(arr, len + 1, used_num)
+            arr.pop()
+            used_num[i] = False
+
+n, m = list(map(int, input().split()))
+
+nums = [i+1 for i in range(n + 1)]
+used_num = [False] * (n+1)
+back_tracking([], 0, used_num)
diff --git "a/\355\225\234\352\260\200\354\235\200/15650.py" "b/\355\225\234\352\260\200\354\235\200/15650.py"
new file mode 100644
index 0000000..727dfc8
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/15650.py"
@@ -0,0 +1,14 @@
+def backtracking (arr, start):
+    if m == len(arr):
+        print(*arr)
+        return
+    
+    for i in range(start, n+1):
+        arr.append(i)
+        backtracking(arr, i+1)
+        arr.pop()
+        
+    
+n, m = list(map(int, input().split()))
+s = 1
+backtracking([], s)
\ No newline at end of file
diff --git "a/\355\225\234\352\260\200\354\235\200/24060.py" "b/\355\225\234\352\260\200\354\235\200/24060.py"
new file mode 100644
index 0000000..06174f7
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/24060.py"
@@ -0,0 +1,54 @@
+#merge sort
+def merge_sort(arr, tmp, p, r, k):
+    global count, result
+    if p<r:
+        q = (p+r)//2
+        merge_sort(arr, tmp, p, q, k)
+        merge_sort(arr, tmp, q+1, r, k)
+        merge(arr, tmp, p, q, r, k)
+
+def merge(arr, tmp, p, q, r, k):
+    global count, result
+    i, j, t = p, q+1, 0
+
+    while i <= q and j <= r:
+        if arr[i] <= arr[j]:
+            tmp[t] = arr[i]
+            i += 1
+        else:
+            tmp[t] = arr[j]
+            j += 1
+        t += 1
+        count += 1
+        if count == k:
+            result = tmp[t-1]
+
+    while i <= q:
+        tmp[t] = arr[i]
+        i += 1
+        t += 1
+        count += 1
+        if count == k:
+            result = tmp[t - 1]
+
+    while j <= r:
+        tmp[t] = arr[j]
+        j += 1
+        t += 1
+        count += 1
+        if count == k:
+            result = tmp[t - 1]
+
+    for i in range(t):
+        arr[p + i] = tmp[i]
+
+
+n, k = map(int, input().split())
+a = list(map(int, input().split()))
+
+count = 0  # 저장 횟수
+result = -1  # K번째 저장되는 수
+
+tmp = [0] * n
+merge_sort(a, tmp, 0, n - 1, k)
+print(result if result != -1 else -1)
\ No newline at end of file
diff --git "a/\355\225\234\352\260\200\354\235\200/4949.py" "b/\355\225\234\352\260\200\354\235\200/4949.py"
new file mode 100644
index 0000000..d937eed
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/4949.py"
@@ -0,0 +1,28 @@
+import sys
+
+while True:
+    state = True
+    stack = []
+    commands = list(sys.stdin.readline().rstrip())
+    if commands == ['.']: # command는 list이기 때문에 []리스트로 일치 판별
+        break
+    for char in commands:
+        if char == '(':
+            stack.append('(')
+        elif char == '[':
+            stack.append('[')
+        elif char == ')':
+            if stack and stack.pop() == '(':
+                state = True
+            else:
+                state = False
+                break
+        elif char == ']':
+            if stack and stack.pop() == '[':
+                state = True
+            else :
+                state = False
+                break
+    if stack:
+        state = False #stack이 비었을 때만 yes
+    print('yes' if state else 'no')
\ No newline at end of file
diff --git "a/\355\225\234\352\260\200\354\235\200/B10828.py" "b/\355\225\234\352\260\200\354\235\200/B10828.py"
new file mode 100644
index 0000000..2e42fc0
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/B10828.py"
@@ -0,0 +1,23 @@
+import sys
+
+stack = []
+n = int(sys.stdin.readline())
+for _ in range(n):
+    command = list(sys.stdin.readline().split())
+    if command[0] == "push" :
+        stack.append(command[1])
+
+    elif command[0] == "pop" :
+        if(stack) : print(stack.pop())
+        else : print(-1)
+
+    elif command[0] == "size":
+        print(len(stack))
+
+    elif command[0] == "empty":
+        if(stack): print(0)
+        else : print(1)
+
+    else :
+        if(stack) : print(stack[-1])
+        else : print(-1)
diff --git "a/\355\225\234\352\260\200\354\235\200/B10845.py" "b/\355\225\234\352\260\200\354\235\200/B10845.py"
new file mode 100644
index 0000000..b9dfc7c
--- /dev/null
+++ "b/\355\225\234\352\260\200\354\235\200/B10845.py"
@@ -0,0 +1,18 @@
+import sys
+
+queue = []
+n = int(sys.stdin.readline())
+for _ in range(n):
+    command = list(sys.stdin.readline().split())
+    if command[0] == "push":
+        queue.append(command[1])
+    elif command[0] == "pop":
+        print(queue.pop(0) if queue else -1)
+    elif command[0] == "size":
+        print(len(queue))
+    elif command[0] == "empty":
+        print(0 if queue else 1)
+    elif command[0] == "front":
+        print(queue[0] if queue else -1)
+    else: #back 
+        print(queue[-1] if queue else -1)
\ No newline at end of file