def main():
print("Creating a new queue...")
q = LinkedListQueue()
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Adding 10 to the queue...")
q.enqueue(10)
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Adding 20 30 40 50 in this order...")
q.enqueue(20)
q.enqueue(30)
q.enqueue(40)
q.enqueue(50)
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Dequeue 3 times...")
for i in range(3):
q.dequeue()
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Adding 10 elements...")
for i in range(10):
q.enqueue(i)
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
