Explanation: The code rotates the position of the boxes by 1, then by 3.
E.g. it returns to its original position.
The combinations of the numbers are therefore:
- Get the first box: rotate 0, rotate 0.
- Get the second box: rotate 1, rotate 3.
- Get the third box: rotate 2, rotate 2.
- Get the fourth box: rotate 3, rotate 1.