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 plane is taking off. Sentence 2: An air plane is taking off.
Example output: 5
Example explanation: Here both statements are talking about the same thing hence it will be classified as a 5.
Q: Sentence 1: The tech-heavy Nasdaq Composite Index .IXIC was off 0.11 percent, or 1.78 points, at 1,594.13. Sentence 2: The broader Standard & Poor's 500 Index .SPX was down 0.04 points, or 0 percent, at 971.52.
A:
1