Bus solved
You have a grid of 16 squares, six of which are filled and rest are blanks, on one square rests a cube.
Your move is to roll the cube through 90 degree so that it moves to an adjacent square. If you roll the cube on to a filled square, the blue color is picked up on one face of the cube. If you roll a filled color face of the cube on to a blank square, the color is put down again. (In general, whenever you roll the cube, the two faces that come into contact swap colors.)
Your job is to get all six filled color squares on to the six faces of the cube at the same time. Count your moves and try to do it in as few as possible.