n=15;
m=8;
road=[|1,14,1664|
1,15,9705|
1,4,1253|
1,13,8584|
1,6,596|
1,5,4817|
1,10,711|
1,3,9624|
1,7,191|
1,8,311|
1,9,3213|
1,2,125|
1,11,3107|
1,12,8855|];