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: John lost in the second round of the Valencia Open 500 to Jeremy Chardy 6-7(7), 3-6. He and partner, Feliciano Lopez will face Alexander Peya and Bruno Soares tomorrow in the quarterfinals of doubles.  Responser: Who's surprised? He doesn't seem to have any killer instinct.
