*-----------*
|...|6.9|..7|
|.2.|.7.|59.|
|...|.3.|.64|
|---+---+---|
|.9.|4..|...|
|87.|1.5|.29|
|...|..7|.1.|
|---+---+---|
|54.|.1.|...|
|.39|.5.|.4.|
|7..|9.6|...|
*-----------*