Description: Solve each of the 10 levels by filling in the gray squares to make the difference of the black squares, both rows and columns. Careful though: boxes can have a pair that must contain the same number. Give the game your best shot!
Instuctions: Black - Open, Gray - Total.
Hover over a box. Type a number.
Box A = Box A, Box B = Box B, and so on...
Highest possible number is the current level.