WHITE TO PLAY AND WIN
Below I give you the solution for those that cannot find the solution themself.
Do you want a tip? If no, then dont read any further.
If yes, then I can only say that it involves a minor promotion.
Only look at the solution if you have solved the puzzle!
White to play and win
[...] 1.♖c8+ ♖xc8 (1...♔xb7 2.♖xd8) 2.♕xa7+ ♔xa7 3.bxc8=♘+ ♔a6 4.♘xe7
Until next time!