*-----------*
|..5|.32|...|
|8..|...|.4.|
|.39|...|..7|
|---+---+---|
|9..|..1|.72|
|..2|.9.|4..|
|57.|4..|..8|
|---+---+---|
|1..|...|98.|
|.6.|...|..4|
|...|68.|2..|
*-----------*