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: http://www.opengdfsuez.com/tips.php?detail=498584&language=uk  Responser: Congrats on the doubles title & the great run in singles!
