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.

Q: Sentence 1: Yahoo agrees to buy Tumblr for $1.1 billion cash Sentence 2: Yahoo to Buy Tumblr for $1.1 Billion

A: 5
****
Q: Sentence 1: A bird sits in a tree. Sentence 2: A bird sits in a leafless tree.

A: 4
****
Q: Sentence 1: Also weighing on the market was news that General Motors GM.N planned to issue $10 billion in debt, in part to plug a hole in its pension plan. Sentence 2: Also hurting was news General Motors GM.N was to issue $10 billion in debt, in part to plug a hole in its pension plan.

A:
5
****