7
0 21 22 18 12 17 16 
21 0 9 9 13 8 9 
22 9 0 6 14 7 8 
18 9 6 0 12 5 6 
12 13 14 12 0 9 6 
17 8 7 5 9 0 3 
16 9 8 6 6 3 0