UVA783 Trains

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=9&page=show_problem&problem=724 [PDF](https://uva.onlinejudge.org/external/7/p783.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA783/f18b69e092a55d7d3a2bee757f8b21d2a1bdadde.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA783/4468198830edc262d658786fbb7b32e9beb96f03.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA783/98818dcf25619381ec35f3a436992ab1df712ca9.png)