*-----------*
|.1.|.98|...|
|.64|17.|..9|
|.87|6..|...|
|---+---+---|
|17.|...|...|
|6..|4.1|..8|
|...|...|.12|
|---+---+---|
|...|..7|89.|
|4..|.13|26.|
|...|84.|.3.|
*-----------*