*-----------*
|...|...|...|
|..1|4..|29.|
|3.8|..7|.4.|
|---+---+---|
|...|..8|7.1|
|8..|275|..3|
|7.2|6..|...|
|---+---+---|
|.9.|5..|6.2|
|.23|..1|4..|
|...|...|...|
*-----------*