Put a digit from 1 to 9 in each cell of the grid, so that each digit occurs exactly once in each column, row and bolded 3x3-box. A big wall between two neighboring cells means, that the sum of the digits in these cells is either 10 or 11. All possible walls are drawn in the grid.
Solution code: Row 8, followed by column 5.
on 30. August 2021, 00:03 by Realshaggy
Added online-solving link, revised tags.
on 10. September 2013, 20:22 by CHalb
Sehr spaßiges Rätsel.
on 17. July 2013, 13:15 by r45
dito.
on 17. July 2013, 10:19 by cornuto
hat mir sehr gut gefallen.