# coding=utf-8

class Stack(object):
    def __init__(self):
        self.data = []

    def pop(self):
        return self.data.pop()

    def push(self, element):
        self.data.append(element)

    def top(self):
        return self.data[-1]

    def isEmpty(self):
        return len(self.data) == 0

class Queue(object):
    def __init__(self):
        self.data = []

    def enqueue(self, element):
        self.data.append(element)

    def dequeue(self):
        return self.data.pop(0)

    def isEmpty(self):
        return len(self.data) == 0

if __name__ == "__main__":
    stack = Stack()
    print("stack operation...")
    print("push 1, 2, 3")
    stack.push(1)
    stack.push(2)
    stack.push(3)
    print("top", end=' ')
    print(stack.top())
    print("pop all elements:")
    while(not stack.isEmpty()):
        print(stack.pop())

    print()

    queue = Queue()
    print("queue operation...")
    print("enqueue 1,2,3")
    queue.enqueue(1)
    queue.enqueue(2)
    queue.enqueue(3)
    print("dequeue all elements")
    while(not queue.isEmpty()):
        print(queue.dequeue())