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: Plastic toys are floating in water. Sentence 2: The ladies are performing a dance.
Example Output: 0

Example Input: Sentence 1: Algerian priest to lecture about Christian heritage in N. Africa Sentence 2: Telstra applies to list China site in NY
Example Output: 0

Example Input: Sentence 1: Three individuals are posing on skis behind a "no skiing" sign. Sentence 2: Three people on skis are standing behind a no skiing sign.
Example Output:
4