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 dog is running through a backyard full of leaves. Sentence 2: Three dogs run through a field.
3

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

Sentence 1: A couple are walking. Sentence 2: Some men are sawing.

0