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 dog with a red toy in it's mouth. Sentence 2: A brown dog is carrying a stick in its mouth.
Example Output: 2

Example Input: Sentence 1: Seniors would then have to pay 50 percent of their drug costs up to $3,450. Sentence 2: Above that, Medicare would pay 90 percent of all drug costs.
Example Output: 2

Example Input: Sentence 1: The two dogs are running on the grass. Sentence 2: Two dogs are playing in the grass.
Example Output:
4