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: Baltimore! Tomorrow (10/4) I'll be at Red Emma's cafe from 8-10pm for an informal meetup. Come hang out with me and other Warm Bodies fans, have a drink, get your books or napkins signed. http://www.redemmas.org  Responser: Baltimore? Berlin it is where we need you!
