Task: Analyze the tweet's emotional connotations and classify it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best portray the tweeter's mental state.
Tweet: @MendipHillsAONB do we think the swallows and swifts have gone? Photo'd 3 nights ago, not seen since. #sad #Autumn
This tweet contains emotions: 
pessimism, sadness