7
0 25 25 20 13 17 17 
25 0 10 9 14 10 10 
25 10 0 7 16 8 8 
20 9 7 0 13 5 5 
13 14 16 13 0 12 8 
17 10 8 5 12 0 4 
17 10 8 5 8 4 0