7
0 30 28 23 16 22 22 
30 0 12 11 16 10 10 
28 12 0 9 16 10 10 
23 11 9 0 13 7 7 
16 16 16 13 0 10 6 
22 10 10 7 10 0 4 
22 10 10 7 6 4 0