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.

Ex Input:
Sentence 1: US Cannot 'Conclusively Determine' Chemical Weapons Use in Syria Sentence 2: U.S. Sees No Conclusive Evidence of Chemical Arms Use by Syria

Ex Output:
5


Ex Input:
Sentence 1: A man is riding a skateboard. Sentence 2: A woman is cutting a potato.

Ex Output:
0


Ex Input:
Sentence 1: Sens. John Kerry and Bob Graham declined invitations to speak. Sentence 2: The no-shows were Sens. John Kerry of Massachusetts and Bob Graham of Florida.

Ex Output:

4