PlaySudoku.us
Expert · Puzzle #152
3
3
6
4
8
6
2
1
5
1
8
4
7
3
8
3
7
9
7
5
9
4
3
5
2
"Continuous effort — not strength or intelligence — is the key to unlocking our potential." — Winston Churchill
"Continuous effort — not strength or intelligence — is the key to unlocking our potential." — Winston Churchill
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.