The Towers of Hanoi is a puzzle consisting of three posts and several rings of various sizes. The initial configuration of the game is that all the rings are stacked in decreasing order of size on one post. The object of the game is to move all the rings from one post to another subject to two rules: only one ring can be moved at a time, and at no time can one ring be placed on top of a smaller ring. The number of steps necessary to solve this puzzle is exponential in the number rings.