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: If you receive Social Security benefits, see the article below regarding the announcement that there will be a 1.7% COLA increase beginning January 2013.  Responser: well, that's wonderful considering they cut my benefit in half at the beginning of this year
