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 man is playing a flute. Sentence 2: A man is playing a bamboo flute.
4

Sentence 1: Close-up of a hummingbird. Sentence 2: A closeup of a hummingbird flying.
4

Sentence 1: The man in the red shirt is climbing the side of a mountain. Sentence 2: A man is climbing the side of a mountain.

4