class queue():
    
    # Constructs an empty queue
    def __init__(self):
        self.L = []

    # Enqueue appends items at back of list
    def enqueue(self, item):
        self.L.append(item)

    # Dequeue removes items from front of list. This method is not efficient 
    def dequeue(self):
        item = self.L.pop(0)
        return item
    
    # Shows the queue as a list
    def __repr__(self):
        return str(self.L)
    
    def isEmpty(self):
        return len(self.L) == 0