UVA234 Switching Channels

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=4&page=show_problem&problem=170 [PDF](https://uva.onlinejudge.org/external/2/p234.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA234/5b6f3d74b6dfda690be06f03db7272b7e7bb54ae.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA234/a1fb3aadde44a76ee8d6c854aabe33874d159426.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA234/09886dab27f916347580fd899e68e41af092d0af.png)