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: They know that the video doesn't show a gas chamber. Sentence 2: The bottom line is that the video clip doesn't show a gas chamber.
Example Output: 5

Example Input: Sentence 1: Close-up of a hummingbird. Sentence 2: A closeup of a hummingbird flying.
Example Output: 4

Example Input: Sentence 1: Pro-Russia rebels to hold vote in Ukraine Sentence 2: Syria rebels: We killed Hezbollah men in Lebanon
Example Output:
0