Create a valid Sudoku puzzle: choose a number from 1, 2, 3, 4, 5, 6 for each shaded box. Do not put numbers in the unshaded boxes. The puzzle is only valid if it has exactly one solution. Create a valid Sudoku puzzle: choose a number from 1, 2, 3, 4, 5, 6 for each shaded box. Do not put numbers in the unshaded boxes. The puzzle is only valid if it has exactly one solution