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: A young boy is holding a guitar. Sentence 2: A little boy is playing a guitar.
Example Output: 3

Example Input: Sentence 1: Two soccer players battle for the ball during an intense match. Sentence 2: Two little orange and white dogs are in the snow.
Example Output: 0

Example Input: Sentence 1: WHO spokeswoman Maria Cheng agreed, saying: "It looks very much like an isolated event." Sentence 2: It looks very much like an isolated event, World Health Organization spokeswoman Maria Cheng said.
Example Output:
5