7
0 25 24 18 14 17 17 
25 0 13 13 15 12 12 
24 13 0 8 14 9 9 
18 13 8 0 12 7 7 
14 15 14 12 0 9 5 
17 12 9 7 9 0 4 
17 12 9 7 5 4 0