UVA13123 Christmas Lights

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=871&page=show_problem&problem=5034 [PDF](https://uva.onlinejudge.org/external/131/p13123.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA13123/7238a90e9c612006053e1425566ad2b7fdc26245.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA13123/a8f3ff2b29197a3de451e557f3abfd548efccb67.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA13123/6fade331b496569e80651cde063d57911cd7686b.png)