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: Black train on train tracks. Sentence 2: A train on the train tracks.
Example Output: 4

Example Input: Sentence 1: in  Foxe basin was frozen. Sentence 2: Foxe was mostly frozen.
Example Output: 4

Example Input: Sentence 1: Bush said resistance forces hostile to the U.S. presence "feel like ... the conditions are such that they can attack us there. Sentence 2: There are some who feel like the conditions are such that they can attack us there.
Example Output:
3