input: Write a function to determine if a given sentence is an 'affirmative' sentence or a 'negative' sentence. The function should return "Affirmative" if there are no negation words in the sentence, and "Negative" if there are negation words present. If the input sentence is empty, return "Affirmative".
  
  assert isAffirmativeorNegative("He always comes late but I dont mind.") == "Negative"
  assert isAffirmativeorNegative("She is always on time.") == "Affirmative"
  assert isAffirmativeorNegative("This is not the correct answer.") == "Negative"
  assert isAffirmativeorNegative("I will never do that.") == "Negative"
  assert isAffirmativeorNegative("") == "Affirmative"
output: def isAffirmativeorNegative(sentence):
      negation_words = {"not", "never", "no", "dont", "doesnt", "didnt", "wont", "cant", "shouldnt", "wouldnt", "isnt", "arent", "wasnt", "werent"}
      if not sentence:
          return "Affirmative"
      for word in sentence.split():
          if word.lower() in negation_words:
              return "Negative"
      return "Affirmative"