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: Thanks Cretins for a great time hanging out. You guys are gonna have me buying a vintage bike http://cretins.org/  Responser: Missed you on Saturday on Wait Wait! You were great last week, and I was hoping for a reprise....My favorite comedian on my favorite show. What could be better???
