Can someone give me a hint on what to do...
| * 3 * | * 4 * | 9 5 * |
| * 1 5 | 3 9 2 | * 4 8 |
| * 4 9 | 5 * * | 1 * 3 |
--------------------------
| 1 * 3 | * * * | * * 4 |
| 9 6 2 | 4 * 3 | 5 8 * |
| 4 * * | * * * | 3 * * |
--------------------------
| 5 * * | * 3 7 | 4 1 * |
| 3 * 1 | 8 5 4 | * 7 * |
| * * 4 | * 2 * | 8 3 5 |
Cheers[/code]