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.

Sentence 1: A group of sheep grazing on a hill. Sentence 2: A group of sheep are on a hill.
4

Sentence 1: A man is playing an electronic keyboard. Sentence 2: A band is playing instruments.
1

Sentence 1: A woman is adding oil on fishes. Sentence 2: A woman is pouring water on fish.

2