input: def sentiment_analysis(tweets: List[str]) -> List[str]:
      """
      Classify positive or negative sentiment in a list of tweets.
      >>> sentiment_analysis(['I love this movie!', 'This is the worst day ever.'])
      ['Positive', 'Negative']
      >>> sentiment_analysis(['Happy anniversary!', 'Not a good experience at all.'])
      ['Positive', 'Negative']
      """
output:     positive_words = {'love', 'happy', 'great', 'awesome', 'good'}
      negative_words = {'worst', 'bad', 'terrible', 'not', 'never'}
      
      result = []
      for tweet in tweets:
          words = tweet.lower().split()
          if any(word in positive_words for word in words):
              result.append('Positive')
          elif any(word in negative_words for word in words):
              result.append('Negative')
          else:
              result.append('Neutral')
      
      return result