Task: Categorize the tweet's emotional tone as either 'neutral or no emotion' or identify the presence of one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Dear everyone at HSSU, stop walking with your phones up so I can smile and wave at you and you can smile and wave back :(
This tweet contains emotions: 
sadness