The objective of Sudoku is to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3x3 subgrids contain all of the digits from 1 to 9.
| 2 | 6 | 7 | 8 | 5 | 3 | 1 | 4 | 9 |
| 1 | 5 | 3 | 2 | 4 | 9 | 6 | 7 | 8 |
| 8 | 4 | 9 | 6 | 1 | 7 | 5 | 3 | 2 |
| 3 | 1 | 4 | 7 | 9 | 2 | 8 | 5 | 6 |
| 7 | 2 | 6 | 5 | 3 | 8 | 9 | 1 | 4 |
| 9 | 8 | 5 | 4 | 6 | 1 | 3 | 2 | 7 |
| 4 | 7 | 2 | 9 | 8 | 5 | 7 | 6 | 1 |
| 5 | 3 | 1 | 7 | 2 | 6 | 4 | 8 | 9 |
| 6 | 9 | 8 | 1 | 7 | 4 | 2 | 3 | 5 |
Solution:
| 2 | 6 | 7 | 8 | 5 | 3 | 1 | 4 | 9 |
| 1 | 5 | 3 | 2 | 4 | 9 | 6 | 7 | 8 |
| 8 | 4 | 9 | 6 | 1 | 7 | 5 | 3 | 2 |
| 3 | 1 | 4 | 7 | 9 | 2 | 8 | 5 | 6 |
| 7 | 2 | 6 | 5 | 3 | 8 | 9 | 1 | 4 |
| 9 | 8 | 5 | 4 | 6 | 1 | 3 | 2 | 7 |
| 4 | 7 | 2 | 9 | 8 | 5 | 7 | 6 | 1 |
| 5 | 3 | 1 | 7 | 2 | 6 | 4 | 8 | 9 |
| 6 | 9 | 8 | 1 | 7 | 4 | 2 | 3 | 5 |