*-----------*
|1.4|8..|...|
|.2.|.9.|.5.|
|...|...|19.|
|---+---+---|
|...|..6|..3|
|2.6|3.1|7.9|
|4..|2..|...|
|---+---+---|
|.87|...|...|
|.4.|.1.|.7.|
|...|..3|9.6|
*-----------*