7
0 23 23 19 15 18 18 
23 0 10 8 10 7 7 
23 10 0 8 16 9 9 
19 8 8 0 12 5 5 
15 10 16 12 0 9 7 
18 7 9 5 9 0 2 
18 7 9 5 7 2 0