a---b---c---d---e---f | | | | | | g---h---i---j---k---l | | | | | | m---n---o---p---q---r | | | | | | s---t---u---v---w---x | | | | | | y---z---A---B---C---D | In a 4x5 grid of squares, the value in each square is determined by the sum of the digits placed at its four corners. Place any digit from 1-9 at each corner. The four corners of each square must be different. Try to achieve as many unique sums as possible. |
Source: Original.