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: Pres Obama signed new #sanctions against #Iranian regime's shipping + energy sectorsbut will he actually enforce them? Remains 2 be seen.  Responser: Why are your tweets so negative at times? Obama signed new sanctions, end of tweet. Some staffer needs to obviously grow up and quit making you sound like a school yard kid. XOXO.
