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: .@Seattlepi: Sen Cantwell was instrumental in building new Doppler radar that better protects against Pacific storms http://bit.ly/r7ArNm  Responser: it warns of but does not protect against storms... Good work though, I hope this helps all of our forecasts become more accurate.
