Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: finally leaving my first job soon. i've been working here since i was 16. going to be kind of bitter sweet
This tweet contains emotions: 
sadness