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: Boeing's board is also expected to decide at its December meeting whether to offer the airplane for sale to airlines. Sentence 2: It is widely expected to give Bair formal approval to offer the plane for sale to airlines.
Example Output: 2

Example Input: Sentence 1: A man is dieing in an operating room. Sentence 2: A man is kissing a woman in stage.
Example Output: 0

Example Input: Sentence 1: A man with glasses is talking. Sentence 2: A man in a library is talking.
Example Output:
3