(White to Move and Win)

I came across this puzzle today. It definitely is not rocket-science -- but for some reason it impressed me, and I thought I would include it.

1. Rh8 is the winning move (Rg8 wins too on the same principles). This forces black to make a horrible choice: (a) capture the pawn with the rook (1... Rxa7) , from which the rook is lost after the skewering move of 2. Rh7+ (with 3. Rxa7 to inevitably follow); or (b) moving the king from the 7th rank (ex. 1... Kc5 -- it doesn't matter the move), from which white simply queens the pawn (2. a8=Q) and the rook is once again lost (2... Rxa8. 3. Rxa8) (+/-).