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.

Q: Sentence 1: Attack on Nato base in Afghanistan kills 15 Sentence 2: Aid workers freed in Afghanistan raid

A: 1
****
Q: Sentence 1: Clinton lands in India to breathe life into ties Sentence 2: Clinton Warns Against Undermining Grameen Bank

A: 1
****
Q: Sentence 1: A man is playing the guitar. Sentence 2: A man is playing the drums.

A:
2
****