PlaySudoku.us
Hard · Puzzle #216
9
1
4
6
8
6
1
3
7
6
5
3
7
4
1
7
4
2
1
3
8
2
7
6
6
2
5
4
8
The pigeonhole principle explains why 8 clues are never enough to guarantee a unique Sudoku solution.
The pigeonhole principle explains why 8 clues are never enough to guarantee a unique Sudoku solution.
"The cosmos is within us. We are made of star-stuff." — Carl Sagan
"The cosmos is within us. We are made of star-stuff." — Carl Sagan