text: from collections import deque
  
  
  class Queue:
  
      def __init__(self):
          self.queue = deque()
  
      def enqueue(self, elem):
          self.queue.append(elem)
  
      def dequeue(self):
          if not self.is_empty():
              return self.queue.popleft()
          else:
              return -1
  
      def is_empty(self):
          return len(self.queue) == 0
  
  
  def main():
      queue = Queue()
      queue.enqueue(2)
      print(queue.dequeue())
      print(queue.dequeue())
      print(queue.is_empty())
  
  
  if __name__ == '__main__':
      main()
  