How’s this?1) Put your finger on any red card.2) Move your finger LEFT or RIGHT to the nearest black card.3) Move your finger UP or DOWN to the nearest red card.4) Move your finger DIAGONALLY to the nearest black card.5) Now move your finger DOWN or RIGHT to the nearest red card.You’ll always land on the ace of diamonds. The way the grid is set up means that with those directions, a card of the color in the specified direction should always be closest, which (as far as I can tell), is always exactly one card. The instructions essentially limit out the choices in such a way that you always end on the Ace of Hearts.