UVA12550 How do spiders walk on water?

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=441&page=show_problem&problem=3995 [PDF](https://uva.onlinejudge.org/external/125/p12550.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12550/8bbd517f5cee21aaa723927c725269d21c1c5a00.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12550/b3c983d6d9629ed870eabb2d35786617d8e344e6.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12550/b5a88082a1cb8909169f24a6dda453a2bfef3886.png)