input: Write a function to determine whether a given sentence is an 'affirmative' sentence or a 'negative' sentence. Use the function to check if there are any negation words in the sentence and return 'Affirmative' if there are none, otherwise return 'Negative'. If the input sentence is empty, return 'Affirmative'.
  assert isAffirmativeorNegative("He always comes late but I dont mind.") == "Negative"
  assert isAffirmativeorNegative("She will attend the meeting tomorrow.") == "Affirmative"
  assert isAffirmativeorNegative("No one could solve the problem.") == "Negative"
  assert isAffirmativeorNegative("The weather is nice today.") == "Affirmative"
  assert isAffirmativeorNegative("") == "Affirmative"
output: def isAffirmativeorNegative(sentence):
      negation_words = {"no", "not", "never", "none", "nobody", "nothing", "neither", "nor"}
      words = sentence.split()
      for word in words:
          if word.lower() in negation_words:
              return "Negative"
      return "Affirmative"