UVA280 Vertex

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=4&page=show_problem&problem=216 [PDF](https://uva.onlinejudge.org/external/2/p280.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA280/1ddcb69659446002b8d4bc567e61d49dc391a8a0.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA280/06c1ca8285d86e4cd722e1684e0951595fdb093f.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA280/3ed57b8a2bc2ea690c6398cb424a24b9345f6e38.png)