Goblins

def pop_back(deque):
  n = deque.pop()
  return n

def push_back(deque, n):
  deque.append(n)

def pop_front(deque):
  n = deque.pop(0)
  return n

def push_front(deque, n):
  deque.insert(0, n)

def balance():
  if len(d1) < len(d2):
    push_back(d1, pop_front(d2) )
  elif len(d1) > len(d2) + 1:
    push_front(d2, pop_back(d1) )

d1 = []
d2 = []
n = int(input())
for i in range(n):
  cmd = input().split()
  if cmd[0] == '-':
    print(pop_front(d1))
  else:
    if cmd[0] == '+':
      push_back(d2, cmd[1])
    else:
      push_back(d1, cmd[1])
  balance()