7
0 23 23 21 15 18 20 
23 0 8 8 12 9 7 
23 8 0 6 12 7 5 
21 8 6 0 10 5 3 
15 12 12 10 0 9 7 
18 9 7 5 9 0 2 
20 7 5 3 7 2 0