7
0 27 26 21 16 21 21 
27 0 11 10 13 8 8 
26 11 0 9 16 9 9 
21 10 9 0 13 6 6 
16 13 16 13 0 11 7 
21 8 9 6 11 0 4 
21 8 9 6 7 4 0