input: Write a python function to check if the sentence is affirmative or negative.
  assert isAffirmativeorNegative("He always comes late but I dont mind.") == "Negative"
  assert isAffirmativeorNegative("She is always on time.") == "Affirmative"
  assert isAffirmativeorNegative("I cannot believe this is happening.") == "Negative"
  assert isAffirmativeorNegative("Everything is going well.") == "Affirmative"
output: def isAffirmativeorNegative(sentence):
      negative_keywords = {"not", "no", "never", "none", "cannot", "don't", "doesn't", "isn't", "aren't", "wasn't", "weren't"}
      words = set(sentence.lower().split())
      
      if words.intersection(negative_keywords):
          return "Negative"
      else:
          return "Affirmative"