Fifteen 3D

#puzzle

Fifteen is a popular puzzle game invented in 1878 by Noah Chapman. It is a set of identical square dice with applied numbers, enclosed in a square box. The length of the box is four times the length of the side of the dice for a set of 15 elements, so one square field is left blank in the box. The goal of the game is to move the knuckles around the box to arrange them by numbers, preferably making as few movements as possible.