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.

Sentence 1: But the FBI never kept tabs on al-Bayoumi - even though it had received information that he was a Saudi agent, the document says. Sentence 2: But the bureau never kept tabs on al-Bayoumi—despite receiving prior information he was a secret Saudi agent, the report says.
5

Sentence 1: She countersued for $125 million, saying Gruner & Jahr broke its contract with her by cutting her out of key editorial decisions. Sentence 2: She countersued for $125 million, saying G+J broke its contract with her by cutting her out of key editorial decisions and manipulated the magazine's financial figures.
4

Sentence 1: The broader Standard & Poor's 500 Index .SPX advanced 2 points, or 0.24 percent, to 977. Sentence 2: The Nasdaq Composite Index .IXIC was off 6.52 points, or 0.39 percent, at 1,645.66.

1