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: Good Morning -- Greetings from Seoul! Beginning the day here in South Korea on my first mission abroad.  Responser: Safe travels. Bring back ways to get Californians working again...!
