7
0 17 17 14 11 13 13 
17 0 12 9 10 8 8 
17 12 0 7 12 8 8 
14 9 7 0 7 3 3 
11 10 12 7 0 6 4 
13 8 8 3 6 0 2 
13 8 8 3 4 2 0