ab
/: /
/ : / 
dc 
 h....g
 /  /
/ /
ef

 Can you place the numbers 18 at the corners of a cube, such
that each face has the same sum (of its four adjacent corners)?
In how many ways can this be done?
 Can you place different numbers (preferably consecutive) at the corners
of a cube such that the six faces have different sums? Consecutive sums?
 Can you place different numbers (preferably consecutive) on the sides
of a cube such that the eight corners have different sums (of their
three adjacent faces)? Consecutive sums?
