UVA10631 Normals

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=18&page=show_problem&problem=1572 [PDF](https://uva.onlinejudge.org/external/106/p10631.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10631/15ae306f4c53c8880088f3866b1197fc171ca0d1.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10631/47a3a9590f5a0cbb13453f1edcfc183f505f1bab.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10631/4e64e1957afe6b4a033f9f409bd60057cbe6024b.png)