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: A dog is running on the ground. Sentence 2: A girl is tapping her finger nails.
0

Sentence 1: the international atomic energy agency may have been tricked because it was eager for a deal. Sentence 2: the international atomic energy agency plan draws out negotiations for many months.
2

Sentence 1: A girl riding a brown horse. Sentence 2: The jockey is wearing purple and riding a brown horse.

2