An easy one this time

This one should not take long to solve, but it is quite entertaining if you have never seen the idea before. It was composed by one of my favourite endgame composers: Henri Rinck.

As usual, here is the solution to the previous ending:

1. Rd8+ (nothing else works) Kxd8 2. b7 Rb4! (a neat attempt at preventing promotion by luring the king to a square where the c7 pawn can advance with check, clearing the way for the Black king)
3. Kxb4 c5+ 4. Kb5 (vital to let the c-pawn live!) Kc7 5. Ka6 Kb8 6. Kb6 c4 7. a4 c3 8. a5 c2 9. a6 c1=Q 10. a7 mate (just in time!)