Tower of Hanoi
The Tower of Hanoi is a puzzle consisting of three pegs (poles) mounted on a board and n disks of various sizes with holes in their centers. If a disk is on a peg, only a disk of smaller diameter can be placed on top of it. Large disk can not be put on small disks. Given all disks properly stacked on one peg, say peg A, the problem is to transfer the disks to another peg, say peg B, by moving one disk at a time, using peg C as a spare.