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: The word happiness would lose its meaning if it were not balanced by sadness.
This tweet contains emotions: 
anticipation, joy, optimism, sadness