class Stack_structure:
  def __init__(self):
    self.q = Queue_structure()

  def check_empty(self):
    return self.q.check_empty()

  def push_val(self, data):
    self.q.enqueue_operation(data)

  def pop_val(self):
    for _ in range(self.q.size_calculate() - 1):
      dequeued = self.q.dequeue_operation()
      self.q.enqueue_operation(dequeued)
    return self.q.dequeue_operation()

class Queue_structure:
  def __init__(self):
    self.items = []
    self.size = 0

  def check_empty(self):
    return self.items == []

  def enqueue_operation(self, data):
    self.size += 1
    self.items.append(data)

  def dequeue_operation(self):
    self.size -= 1
    return self.items.pop(0)

  def size_calculate(self):
    return self.size

my_instance = Stack_structure()

print('Menu')
print('push <value>')
print('pop')
print('quit')

while True:
  my_input = input('What operation would you like to perform ? ').split()

  operation = my_input[0].strip().lower()
  if operation == 'push':
    my_instance.push_val(int(my_input[1]))
  elif operation == 'pop':
    if my_instance.check_empty():
      print('栈为空。')
    else:
      print('删除的值为：', my_instance.pop_val())
  elif operation == 'quit':
    break

菜单
push <value>
pop
quit
你想执行什么操作？
push 89
你想执行什么操作？
push 43
你想执行什么操作？
push 76
你想执行什么操作？
push 56
你想执行什么操作？
pop
删除的值为： 56
你想执行什么操作？
quit