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: Attack on Nato base in Afghanistan kills 15 Sentence 2: Aid workers freed in Afghanistan raid
1

Sentence 1: A dog with a red toy in it's mouth. Sentence 2: A brown dog is carrying a stick in its mouth.
2

Sentence 1: Two women shopping at a clothing store. Sentence 2: Two women in a clothing store.

5