Evaluate the tweet for the intensity of the emotion sadness. The categories are as follows: 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.
Tweet: Do not grow weary in doing good. The treadlines are better than deadlines.' @billclinton #CGI2016
0: no sadness can be inferred