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 woman rides a horse. Sentence 2: A woman is riding a horse.
Example Output: 5

Example Input: Sentence 1: A field of black faced sheep. Sentence 2: A black faced sheep.
Example Output: 3

Example Input: Sentence 1: A baby elephant is eating. Sentence 2: A baby elephant eats a sapling.
Example Output:
4