*-----------*
|..3|9..|4..|
|9..|7..|2..|
|487|...|.6.|
|---+---+---|
|...|.1.|5.2|
|.5.|.8.|.3.|
|3.1|.5.|...|
|---+---+---|
|.3.|...|754|
|..9|..2|..6|
|..8|..5|3..|
*-----------*