7
0 31 29 23 19 22 22 
31 0 16 14 16 13 13 
29 16 0 10 18 11 11 
23 14 10 0 14 7 7 
19 16 18 14 0 11 7 
22 13 11 7 11 0 4 
22 13 11 7 7 4 0