Classify the emotions found in the tweet "@MendipHillsAONB do we think the swallows and swifts have gone? Photo'd 3 nights ago, not seen since. #sad #Autumn". Select from the following: anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust. If the tweet is emotionless, reply "neutral or no emotion".
pessimism, sadness