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: tin foil hat for the dog face, what size do u wear? Sentence 2: tin foil hat for the sarg, what size do u wear?
3

Sentence 1: Someone standing on a snowy mountain, watching a plane. Sentence 2: A man stands on a mountain, watching a plane.
4

Sentence 1: A law is constitutional if it does not conflict with the Constitution. Sentence 2: To be unconsititutional means to violate the constitution.

4