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: Had an amazing 2 weeks here at the @usopen Thanks @rajeevram318 for a great run to the finals! See you all next year  Responser: Great job! Here's some support from San Diego!
