7
0 30 26 21 17 21 21 
30 0 12 11 13 9 9 
26 12 0 9 17 9 9 
21 11 9 0 14 6 6 
17 13 17 14 0 12 8 
21 9 9 6 12 0 4 
21 9 9 6 8 4 0