Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: Congratulations to Reston Citizens Association's Citizen of the Year, Marion Stillson. She's been serving our community for more than 30 years and is not slowing down.  Responser: Congratulations Marion Stillson!
