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 toy train is striking a toy car. Sentence 2: A toy train strikes a toy car.
Example Output: 5

Example Input: Sentence 1: Man arrested over double murder Sentence 2: WA man arrested in police drug raid
Example Output: 1

Example Input: Sentence 1: mexican president felipe calderon has sent 2800 special agents and soldiers to sinaloa due to the high degree of organized crime and drug trafficking. Sentence 2: mexican president felipe calderon has sent 2800 special agents and soldiers to sinaloa to fight drug trafficking.
Example Output:
5