7
0 19 18 13 11 13 12 
19 0 11 10 10 8 9 
18 11 0 7 13 7 8 
13 10 7 0 10 4 5 
11 10 13 10 0 8 5 
13 8 7 4 8 0 3 
12 9 8 5 5 3 0