input: 
  def reverse_combined_strings(string1: str, string2: str) -> str:
      """Combine two given strings and return the reversed result.
      >>> reverse_combined_strings("Hello ", "world!")
      '!dlrow olleH'
      >>> reverse_combined_strings("abc", "def")
      'fedcba'
      """
  
output:     combined = string1 + string2
      return combined[::-1]