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: three little boys cover themselves with bubbles. Sentence 2: Three children standing by a pool are covered in foam bubbles.
Example Output: 4

Example Input: Sentence 1: Allegiant shares rose $4, or $17.2 percent, to $27.43 in Thursday morning trading on the Nasdaq Stock Market. Sentence 2: Allegiant's stock closed Wednesday at $23.40, up 64 cents, in trading on the Nasdaq market.
Example Output: 2

Example Input: Sentence 1: Nine Pakistani troops killed in militant ambush Sentence 2: Trade: Pakistan, India agree to take it a step ahead
Example Output:
1