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 black and brown dog walks through the snow near a building. Sentence 2: An older man stands outside a old boarded up building.
Example Output: 1

Example Input: Sentence 1: Fallen US firefighters brought home Sentence 2: Wall Street ends slightly lower
Example Output: 0

Example Input: Sentence 1: Ryanair in new bid for Aer Lingus Sentence 2: Ryanair chief hails report findings
Example Output:
1