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: Ten years ago today, I was driving to my clinic at Earl K Long Hospital when the radio announced that both Twin Towers had been hit. Do you remember where you were?  Responser: Yes. And I will never forget. :(
