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! First #GoldMedal of the #RioOlympics2016 goes to #WVU student #GinnyThrasher http://www.nbcolympics.com/news/usas-virginia-thrasher-wins-first-gold-medal-olympics  Responser: Congratulations from West Virginia
