UVA11972 Round Trip

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=229&page=show_problem&problem=3123 [PDF](https://uva.onlinejudge.org/external/119/p11972.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11972/52b9ef59b38186ee80898af18c170f504852edf9.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11972/ed14e8f86253fea4324ddde56155483c75644261.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11972/50294b1d944d12aab998a274b58dab413d59c69a.png)