PlaySudoku.us
Medium · Puzzle #690
8
2
5
7
9
4
7
8
6
3
7
4
6
2
8
6
7
6
2
7
4
8
7
8
1
6
3
4
6
8
3
1
6
7
8
5
Finnish mathematician Arto Inkala created what is widely considered the world's hardest Sudoku in 2012.
Finnish mathematician Arto Inkala created what is widely considered the world's hardest Sudoku in 2012.
"Losing is not the worst thing that can happen to you in chess. Not trying is." — anonymous chess proverb
"Losing is not the worst thing that can happen to you in chess. Not trying is." — anonymous chess proverb