Combination

A popular puzzle, invented in 1878 by Noah Chapman. It is a set of identical square knuckles with the figures put in a square box. The length of the side of the box is four times the length of the side of the knuckles for a set of 15 elements, respectively, in the box one square field remains unfilled. The goal of the game is to move the knuckles around the box, to order them by numbers, preferably making as few movements as possible.