Task: Determine the prevailing emotional tone of the tweet, categorizing it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that most accurately represent the tweeter's mental state.
Tweet: @BorisJohnson unhappy about the cost of leaving the EU ? If only you had published your letter outlining the reasons to stay instead. Idiot.
This tweet contains emotions: 
anger, sadness