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: Here's a link to the trailer for the film I shot last fall with Will Smith and Alec Baldwin. It will be in theaters Christmas Day http://www.si.com/nfl/2015/08/31/watch-concussion-movie-head-injuries  Responser: Really? Christmas Day ?? Sweet !
