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: Under NASD regulations, Mr. Young can file a response and request a hearing before an NASD panel. Sentence 2: The analyst, already let go by Merrill, can request a hearing before a NASD panel.
Example Output: 3

Example Input: Sentence 1: Thousands evacuated in Moscow metro fire Sentence 2: Thousands evacuated after fire breaks out in Moscow Metro
Example Output: 5

Example Input: Sentence 1: Apple Computer's new online music service sold more than 1 million songs during its first week of operation, the company said Monday. Sentence 2: Apple Computer Inc. said Monday it exceeded record industry expectations by selling more than 1 million songs since the launch of its online music store a week ago.
Example Output:
5