1
5
3
2
4
7
6
3
5
7
3
8
1
1
3
5
9
3
8
1
2
7
2
4
9
7
3
3
2
8
7
9
6
8
7
9
3
At peak Sudoku popularity in 2006, over 600 different Sudoku books were published in a single year.
At peak Sudoku popularity in 2006, over 600 different Sudoku books were published in a single year.
At peak Sudoku popularity in 2006, over 600 different Sudoku books were published in a single year.
At peak Sudoku popularity in 2006, over 600 different Sudoku books were published in a single year.