input: from typing import List
  
  def reverse_words(str: str) -> str:
      """ Reverse the order of words in given string.
      >>> reverse_words("Hello world")
      'world Hello'
      >>> reverse_words("Hi how are you")
      'you are how Hi'
      """
      return " ".join(str.split()[::-1])
output:     words = str.split()
      reversed_words = words[::-1]
      return " ".join(reversed_words)