*-----------*
|5..|.28|...|
|..8|1..|..3|
|.6.|...|.9.|
|---+---+---|
|.54|..1|..7|
|8..|4.2|..5|
|1..|8..|32.|
|---+---+---|
|.8.|...|.3.|
|4..|..9|5..|
|...|26.|..9|
*-----------*