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: Into the Quarterfinals tomorrow at Hobart International with a 6-2,6-2 win over Arruabarrena! The seagulls stole the spotlight all night! First time I've had a let called due to bird interference  Responser: Keep climbing Shelby
