input: 
  
  from typing import List
  
  def reverse_words(str: str) -> str:
      """Reverse the order of words in a given string.
      >>> reverse_words("Hello world")
      "world Hello"
      >>> reverse_words("Python is great")
      "great is Python"
      """
      return " ".join(str.split()[::-1])
  
output:     words = str.split()
      reversed_words = words[::-1]
      return " ".join(reversed_words)