*-----------*
|..3|2..|.7.|
|...|.3.|51.|
|.6.|..5|4..|
|---+---+---|
|39.|..7|..5|
|...|.5.|...|
|7..|1..|.83|
|---+---+---|
|..8|7..|.5.|
|.74|.9.|...|
|.2.|..6|7..|
*-----------*