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: Brisk 3 clicks to blow off those weekend cobwebs!!! 300kcals down, perfect start to the day!!!  Responser: Neither... my usual trek around the park... not flat, but not too hilly either...
