StivStiv 162k1212 gold badges588588 silver badges875875 bronze badges $endgroup$ 2 $begingroup$ Dang that is difficult. I'm not used to contemplating like that. Thanks for that approach. $endgroup$ tazboyTo resolve medium Sudoku puzzles, all you need is really a pencil and eraser (or simply a digital Sudoku app or Web site). It can even be helpful