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: Today I'm on Wait Wait Don't Tell Me even though the link goes to last weeks show http://www.npr.org/programs/wait-wait-dont-tell-me/  Responser: listening RIGHT NOW
