input: def combine_and_reverse_strings(words1: str, words2: str) -> str:
      """
      Combine two strings and reverse the result.
      >>> combine_and_reverse_strings("Hello ", "world!")
      '!dlrow olleH'
      >>> combine_and_reverse_strings("Python", " is cool!")
      '!looc si nohtyP'
      """
output:     combined = words1 + words2
      return combined[::-1]