input: from typing import Tuple
  
  
  def replace_string(sentence: str, old_word: str, new_word: str) -> Tuple[str, str]:
      """ Replace the old word with the new word in the given sentence and return both
      the new sentence and the original sentence as a tuple.
      >>> replace_string("I love walking on the beach", "walking", "swimming")
      ("I love swimming on the beach", "I love walking on the beach")
      >>> replace_string("Python is amazing", "Python", "Java")
      ("Java is amazing", "Python is amazing")
      """
      new_sentence = sentence.replace(old_word, new_word)
      return new_sentence, sentence
output:     new_sentence = sentence.replace(old_word, new_word)
      return new_sentence, sentence