class queue:
  def __init__(self,inputlist=[]):
    self.items = inputlist.copy()

  def queueup(self, item):
    self.items.append(item)

  def queuedown(self):
    return self.items.pop(0)

  def length(self):
    return len(self.items)

  def isEmpty(self):
    if len(self.items) == 0:
      return True
    else:
      return False