7
0 25 23 19 15 17 18 
25 0 12 10 12 10 9 
23 12 0 8 14 10 9 
19 10 8 0 10 6 5 
15 12 14 10 0 8 5 
17 10 10 6 8 0 3 
18 9 9 5 5 3 0