Fifty Squares of Grey: The Spanking-New Sudoku Variant

Whips, handcuffs . . . sudoku? When you're in the mood for some masochistic pleasure, this variant of the popular puzzle will satisfy your desires. Each 10x10 grid is divided into ten regions of 5x2. Play like regular sudoku, except using numbers 0-9. Then comes the twist: each sudoku also has five 10-square grey regions to complete a total of 50 squares of grey.