7
0 25 23 18 12 16 17 
25 0 10 9 13 9 8 
23 10 0 7 15 9 8 
18 9 7 0 12 6 5 
12 13 15 12 0 10 7 
16 9 9 6 10 0 3 
17 8 8 5 7 3 0