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: 4 killed in shrine bombing in northwest Pakistan Sentence 2: 12 killed in U.S. drone strike in NW Pakistan
Example Output: 1

Example Input: Sentence 1: A boy is playing with a toy. Sentence 2: A boy plays a handheld game.
Example Output: 3

Example Input: Sentence 1: A boy is cutting paper. Sentence 2: A man is loading a rifle.
Example Output:
0