solved the sudoku puzzle at 39:44

5 4 1 | 7 3 2 | 9 6 8
8 7 6 | 1 9 5 | 3 4 2
3 2 9 | 6 4 8 | 1 7 5
-------------------------
6 1 3 | 2 5 4 | 7 8 9
7 8 5 | 9 1 6 | 4 2 3
4 9 2 | 3 8 7 | 6 5 1
-------------------------
9 5 7 | 8 6 1 | 2 3 4
2 3 8 | 4 7 9 | 5 1 6
1 6 4 | 5 2 3 | 8 9 7

real