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: Had a great day in Missouri with Democratic Senate candidate Jason Kander today. As part of his bus tour, we stopped at A Slice of Pie in Rolla, MO where I bought one of their famous strawberry rhubarb pies!  Responser: Great for you. While you eat that pie, I hope you reflect on those at Standing Rock who are fighting for your grandchildren in hopes of having clean, free water to drink and play in.
