*-----------*
|..4|.8.|7..|
|8..|7..|...|
|...|.54|2..|
|---+---+---|
|7..|6..|.2.|
|.65|1.3|87.|
|.3.|..8|..5|
|---+---+---|
|..3|41.|...|
|...|..7|..9|
|..7|.6.|5..|
*-----------*