Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture the tweeter's mental state.
Tweet: It's my last week at CN! I'm gonna be sad to leave, but this will also be my first planned break since going into animation!
This tweet contains emotions: 
sadness