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: Parked white double decker bus. Sentence 2: A red and white double decker bus is parked.
4

Sentence 1: a black and white cow in hay. Sentence 2: A black and white cow in a pen with hay.
4

Sentence 1: Four black dogs run across the grass. Sentence 2: A dog runs across the grassy field.

2