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: Two people are riding a motorcycle. Sentence 2: Two people are riding a bike.
Example Output: 2

Example Input: Sentence 1: A girl is playing a flute. Sentence 2: A band is playing on a stage.
Example Output: 1

Example Input: Sentence 1: Lacey - welcome back! Sentence 2: Anyway, welcome back.
Example Output:
4