text: class Queue:
      def __init__(self):
          self.ls = []
  
      def push(self, x):
          self.ls.append(x)
  
      def pop(self):
          self.ls = self.ls[1:]
  
      def peek(self):
          return self.ls[0]
  
      def empty(self):
          return len(self.ls) == 0
  