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: @justinbieber Thank u Justin for this amazing concert. I can't believe that only u can provoke these thousand smiles these night#BelieveTour
This tweet contains emotions: 
joy, love, optimism