*-----------*
|4.6|.7.|.2.|
|.3.|6..|...|
|.9.|.13|...|
|---+---+---|
|.84|...|..6|
|7.1|...|5.8|
|3..|...|41.|
|---+---+---|
|...|46.|.5.|
|...|..9|.6.|
|.7.|.2.|1.3|
*-----------*