input: 
  def analyze_sentiment(text):
      """Analyze the sentiment of the given text and categorize it into positive, negative, or neutral.
      >>> analyze_sentiment("I love this product! It's amazing.")
      'positive'
      >>> analyze_sentiment("I hate this product. It's terrible.")
      'negative'
      >>> analyze_sentiment("This product is okay.")
      'neutral'
      """
  
output:     positive_words = ["love", "amazing", "great", "excellent"]
      negative_words = ["hate", "terrible", "awful", "bad"]
      
      text = text.lower()
      words = text.split()
      
      positive_count = sum(1 for word in words if word in positive_words)
      negative_count = sum(1 for word in words if word in negative_words)
      
      if positive_count > negative_count:
          return 'positive'
      elif negative_count > positive_count:
          return 'negative'
      else:
          return 'neutral'