Wyps numeric problem

Here is an interesting position showing the depth of this game.
https://gyazo.com/7ce03585304d2b2b0efe31847a577c92
White to play and win (game finished).

I checked the game and found the very nice mate in four you had made, but sorry to tell you that you had a simple mate in one. I will type it here if you can't find it yourself.

As simple as counting... like a kid from five to nine.
Thanks for reviewing this Nagy !