一定是他自己到capital，可以是别人帮他）

N<=100000

3 ≤  N ≤  100 000 
0 ≤  Si≤ 10^9
 
1 ≤  Vi≤ 10^9
 
The length of each road will not exceed 10 000 
For 20% of the tests, N ≤  2 500 
For 50% of the tests, each town will have at most 2 adjacent roads (i.e., the graph of 
roads will be a line) </div></div></div></div><div class="row"><div class="column"><h4 class="ui top attached block header">输入格式</h4><div class="ui bottom attached segment font-content"><di