Eight standard dice (see pattern) should be arranged to form
a 2x2x2 cubical stack as shown on the right side of the image.
Each die is in contact with three other dice, so there are 12
pairs of surfaces which are in contact.
The following constraint is to fulfill:
Each pair of contact surfaces must have the same number of spots.
Your job is now to arrange the dice so that the number of
visible spots (spots on the 24 non-contact surfaces) becomes a
minimum.
