*-----------*
|.4.|..7|15.|
|...|..3|27.|
|9.7|..1|.83|
|---+---+---|
|...|3.5|...|
|8..|.4.|..2|
|...|8.2|...|
|---+---+---|
|79.|5..|6.8|
|.85|9..|...|
|.34|7..|.9.|
*-----------*