*-----------*
|4..|..5|.98|
|1.8|.3.|...|
|7..|8..|...|
|---+---+---|
|...|..1|87.|
|..7|2.8|5..|
|.13|5..|...|
|---+---+---|
|...|..4|..7|
|...|.8.|3.1|
|95.|7..|..4|
*-----------*