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: Three women are dancing. Sentence 2: The man is dancing.
Example Output: 2

Example Input: Sentence 1: Two die in Syria violence after UN monitors land Sentence 2: Two year doping ban for Contador
Example Output: 0

Example Input: Sentence 1: A group of people sitting around a table with food on it. Sentence 2: A group of people sit around a table with food and beer.
Example Output:
4