Play Tower of Hanoi. Your goal in this game is to move all rings from pile A to pile C and stack them according to the original order.
The Tower of Hanoi is a mathematical game or puzzle consisting of three rods and a number of disks of various diameters, which can slide onto any rod. The puzzle begins with the disks stacked on one rod in order of decreasing size, the smallest at the top, thus approximating a conical shape.
Object of the game is to move all the disks over to Tower 3 (with your mouse). But you cannot place a larger disk onto a smaller disk.