Normal sudoku rules apply. Each of the main diagonals may only contain 3 distinct digits. Digits in a Quadruple circle must be placed at least once in the four cells touching that circle. The cell with the gray circle must contain an odd digit.
Normal sudoku rules apply. Each of the main diagonals may only contain 3 distinct digits. Digits in a Quadruple circle must be placed at least once in the four cells touching that circle. The cell with the gray circle must contain an odd digit.