Evaluate the similarity between them and classify them into classes from 0-5 as follows:
0 : The two sentences are completely dissimilar.
1 : The two sentences are not equivalent, but are on the same topic.
2 : The two sentences are not equivalent, but share some details.
3 : The two sentences are roughly equivalent, but some important information differs/missing.
4 : The two sentences are mostly equivalent, but some unimportant details differ.
5 : The two sentences are completely equivalent, as they mean the same thing.

Q: Sentence 1: A girl is playing a flute. Sentence 2: A band is playing on a stage.

A: 1
****
Q: Sentence 1: Someone is playing piano. Sentence 2: A person is playing a keyboard piano.

A: 4
****
Q: Sentence 1: Nelson Mandela dies aged 95 Sentence 2: Nelson Mandela Dies at Age 95

A:
5
****