For the tweet "Incredibly shocked and disappointed with @united customer service. Really making me rethink flying with them in the future. #unhappy", classify the intensity of the emotion sadness. The possible classifications are: 0: no sadness can be inferred, 1: low amount of sadness can be inferred, 2: moderate amount of sadness can be inferred, 3: high amount of sadness can be inferred.
3: high amount of sadness can be inferred