*-----------*
|9..|28.|6..|
|.74|.5.|..1|
|...|...|.8.|
|---+---+---|
|.43|..2|...|
|5..|834|..6|
|...|7..|42.|
|---+---+---|
|.1.|...|...|
|2..|.7.|81.|
|..5|.16|..2|
*-----------*