input: from typing import List
  
  def sentiment_analysis(tweets: List[str]) -> List[str]:
      """Classify positive and negative sentiment in tweets.
      >>> sentiment_analysis(['I love this product!', 'This is terrible.'])
      ['Positive', 'Negative']
      >>> sentiment_analysis(['It is okay.', 'I hate it.'])
      ['Neutral', 'Negative']
      """
output:     positive_words = {'love', 'great', 'good', 'awesome', 'happy', 'positive'}
      negative_words = {'hate', 'terrible', 'bad', 'awful', 'sad', 'negative'}
      result = []
  
      for tweet in tweets:
          words = set(tweet.lower().split())
          if positive_words & words:
              result.append('Positive')
          elif negative_words & words:
              result.append('Negative')
          else:
              result.append('Neutral')
  
      return result