7
0 29 28 21 17 21 21 
29 0 13 12 14 10 10 
28 13 0 9 17 9 9 
21 12 9 0 14 6 6 
17 14 17 14 0 12 8 
21 10 9 6 12 0 4 
21 10 9 6 8 4 0