*-----------*
|...|.5.|..1|
|.51|.4.|98.|
|9.3|71.|...|
|---+---+---|
|..9|..4|...|
|.8.|3.9|.7.|
|...|6..|2..|
|---+---+---|
|...|.62|7.4|
|.17|.9.|62.|
|2..|.3.|...|
*-----------*