UVA514 铁轨 Rails

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=7&page=show_problem&problem=455 [PDF](https://uva.onlinejudge.org/external/5/p514.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA514/a8f0af9a2adeaeaab1d1906c3f3116afa0c6b444.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA514/03b4e1924e74948bc01f3f42cd5a31502f1c39b6.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA514/7e96780a876f827180dea25139c1c77bbfb94937.png)