#coding:utf8
class Queue():

def __init__(self):<br/>
    self.items = []

def enqueue(self, item):

    self.items.insert(0, item)

def dequeue(self):

    return self.items.pop()

def isEmpty(self):

    return len(self.items) == 0

def size(self):

    return len(self.items)

queue = Queue()

queue.enqueue(1)

queue.enqueue(2)

queue.enqueue(3)

print(queue.size())

print(queue.dequeue())

print(queue.dequeue())

print(queue.dequeue())