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: I got into the most beautiful city in the world, Paris, today. Italy was fun and I had a blast driving around. There were some unexpectedly friendly people, like the Venetian mask seller who offered my sister and I leather keychains for free after we tried on every mask (and bought three).  Responser: My favorite city! Ave fun you two :)
