3
4
7
9
5
1
2
2
1
6
2
5
4
8
1
5
8
6
6
1
7
5
3
9
5
7
2
1
3
9
6
8
7
8
1
Wayne Gould gave his puzzle software to The Times for free, triggering the global Sudoku craze. He made his money from books.
Wayne Gould gave his puzzle software to The Times for free, triggering the global Sudoku craze. He made his money from books.
For Evil puzzles, study the Y-Wing technique: it chains three cells into a forced elimination.
For Evil puzzles, study the Y-Wing technique: it chains three cells into a forced elimination.