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: Economy shrank in Q1 by 2.9%- worst in five years since Obama took office, worse than the 1% projected. Braley's #WashingtonWay is NOT working.  Responser: Joe Biden said this was recovery summer. Oh wait, that was a few years ago.
