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 group of penguins is walking. Sentence 2: A large amount of penguins are heading to the ocean.
Example Output: 3

Example Input: Sentence 1: Four Asian young people sitting in a den or living room. Sentence 2: A girl sitting in a living chair.
Example Output: 1

Example Input: Sentence 1: A black and white photo of an empty train station. Sentence 2: a black and white photo of a cat lying down.
Example Output:
2