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: Africa has unique and tremendous problems with war, overpopulation, starvation and tribalism which makes moving Africa forward hard.
This tweet contains emotions: 
disgust, sadness