Puzzle 22354

I tried to solve Puzzle 22354
http://en.lichess.org/training/22354

I played 1. Rg7+ which is a mate in 5, but it was marked as wrong. The computer said, that the right answer is 1. Nf6+ (what is also a mate in 5). Why should be 1. Rg7+ then wrong?

By the way: great chess side, only some puzzles are annoying, as several users mentioned before.

When the machine looks at the puzzle in the "Analysis Board" it goes with the rook and gets mate in 5 (like you say). I've noticed puzzles with multiple solutions, this should no doubt be one of them.

Are the puzzle and analysis engines the same?

U are right. Wrong valuetion...