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: The broader Standard & Poor's 500 Index <.SPX> gave up 11.91 points, or 1.19 percent, at 986.60. Sentence 2: The technology-laced Nasdaq Composite Index .IXIC declined 16.68 points, or 1.01 percent, at 1,636.94.
Example Output: 1

Example Input: Sentence 1: A total of 17 cases have been confirmed in the southern city of Basra, the Organization said. Sentence 2: A total of 17 confirmed cases of cholera were reported yesterday by the World Health Organisation in the southern Iraqi city of Basra.
Example Output: 4

Example Input: Sentence 1: A boy and a girl is dancing in the rain. Sentence 2: A man and woman is dancing in the rain.
Example Output:
3