7
0 22 21 16 12 16 15 
22 0 11 10 12 8 9 
21 11 0 7 13 7 8 
16 10 7 0 10 4 5 
12 12 13 10 0 8 5 
16 8 7 4 8 0 3 
15 9 8 5 5 3 0