input: 
  def count_down(n: int):
      """ Outputs the numbers from n down to 1 using a while loop.
      >>> count_down(6)
      6
      5
      4
      3
      2
      1
      "Done!"
      >>> count_down(3)
      3
      2
      1
      "Done!"
      """
      while n > 0:
          print(n)
          n -= 1
      print("Done!")
  
output:     while n > 0:
          print(n)
          n -= 1
      print("Done!")