4
5
9
3
7
1
1
9
7
5
4
8
7
1
6
9
4
2
1
5
3
9
9
6
4
2
1
5
7
7
3
9
6
1
4
8
2
6
9
8
1
8
4
7
6
2
1
3
9
8
5
How to Play
- Fill the grid so that every row, column, and 3x3 box contains the digits 1 to 9.
- Select a difficulty level to start a new game.
- Use the number pad or keyboard to fill in cells.
- Relax and enjoy the process.