Implement Stack using Queues.py

class MyStack(object):

    def __init__(self):
        self.stack=[]

    def push(self, x):
        self.stack.append(x)
        return None
        
    def pop(self):
        return self.stack.pop(-1)
        

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

    def empty(self):
        if self.stack==[]:
            return True
        return False


# Your MyStack object will be instantiated and called as such:
# obj = MyStack()
# obj.push(x)
# param_2 = obj.pop()
# param_3 = obj.top()
# param_4 = obj.empty()