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.

Example Input: Sentence 1: Residents return to Texas blast site Sentence 2: Residents return to Fallujah
Example Output: 0

Example Input: Sentence 1: A girl riding on a brown and white horse. Sentence 2: A girl riding a brown horse.
Example Output: 4

Example Input: Sentence 1: A woman shoots a shotgun. Sentence 2: The woman is shooting a rifle.
Example Output:
3