class MyQueue(object):
    # FIFO
    def __init__(self):
        self.queue = []
    
    def peek(self):
        return self.queue[0]
        
    def pop(self):
        if len(self.queue) != 0:
            return self.queue.pop(0)
        
    def put(self, value):
        self.queue.append(value)