240331

#3021
# n = int(input())
# stack = []
# for i in range(n):
#     m = input().split()
#     if m[0] == "push(":
#         stack.append(m[1])
#     elif m[0] == "top()":
#         if len(stack)== 0:
#             print(-1)
#         else:
#             print(stack[-1])
#     elif m[0] == "pop()":
#         if len(stack)!=0:
#             stack.pop()
#     elif m[0] == "size()":
#         print(len(stack))
#     elif m[0] == "empty()":
#         if len(stack) == 0:
#             print("true")
#         else:
#             print("false")
#list
# list.append()
#
# del list[5]
#
# list.pop()
#
# list.insert(2,50)
#
# list.sort()
#
# list.reverse()
#
# max(list)
# min(list)
#
# list.count(10)
#
# list.index(5)  # 5의 처음 발견 위치 리턴

#3104 해결X
# n = int(input())
# queue = []
# for i in range(n):
#     m = input().split()
# 
# 
# 
#     if m[0] == "push(":
#         queue.append(m[1])
#         queue.sort(reverse=True)
#     elif m[0] == "top()":
#         if len(queue)== 0:
#             print(-1)
#         else:
#             print(max(queue))
#     elif m[0] == "pop()":
#         if len(queue)!=0:
#             del queue[0]
# 
#     elif m[0] == "size()":
#         print(len(queue))
# 
#     elif m[0] == "empty()":
#         if len(queue) == 0:
#             print("true")
#         else:
#             print("false")

#5137 pypy3해결
# n = int(input())
# queue = []
# for i in range(n):
#     m = input().split()
#     if m[0] == "+":
#         queue.append(int(m[1]))
#     elif m[0] == "-":
#         if len(queue)!=0:
#             del queue[0]
#     elif m[0] == "?":
#         if len(queue) != 0:
#             print(min(queue))