7
0 21 22 19 13 18 17 
21 0 11 8 12 7 8 
22 11 0 7 15 8 9 
19 8 7 0 10 3 4 
13 12 15 10 0 9 6 
18 7 8 3 9 0 3 
17 8 9 4 6 3 0