hard 9×9 Set 8 Grid Puzzle
5
2
7
1
5
4
2
7
9
1
4
2
9
2
8
5
3
7
6
1
5
3
2
1
6
8
1
4
8
3
7
6
9
5
4
6
2
3
9
1
8
5
7
2