solve the math puzzle

Example 2.7. To find the outcome of the following game of MAIZE you have to determine the leaves first: P P P and working backwards we find TOPPLING DOMINOES P zs ALLA ALL R P P R WILL C P Position: A row of black, white, or gray dominoes. Moves: Left chooses a black or gray domino and topples it either left or right, every domino in that direction also topples and is removed from the game. Right topples a white or gray domino. L C