SP4871 BRI - Bridge

Description

Find a place to build a bridge over the river, so as to minimize total cost of the route between two cities A and B, located on opposite sides of the river. ![](https://cdn.luogu.com.cn/upload/vjudge_pic/SP4871/59e3e98c1f4c52de641f65f0878f87615df4b3a7.png)

Input Format

N/A

Output Format

N/A