north: 80
south: 0
east: 100
west: 0
rows: 8
cols: 10
* * * * * * * * * * 
6 7 8 9 10 11 12 13 14 15 
7 8 9 10 11 12 13 14 15 16 
8 9 10 11 12 13 14 15 16 17 
* * * * * * * * * * 
10 11 12 13 14 15 16 17 18 19 
11 12 13 14 15 16 17 18 19 20 
12 13 14 15 16 17 18 19 20 21