Medium Level 7 (30 clues)

谜题网址: http://cn.sudoku99.com/sudoku9x9/puzzle/823916/
网站: cn.sudoku99.com

1

7

8

2

3

4

7

2

4

9

7

1

2

7

5

8

7

6

1

8

4

5

2

5

3

1

9

4

3

7