UVA11289 Friend or Foe?

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=2264 [PDF](https://uva.onlinejudge.org/external/112/p11289.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11289/0f88e5af324889cc505dc4f6fe4e4da5edaa7638.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11289/209cd76388013cc382eaaa0f7917a97337056a02.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11289/5f68285fa3e18304f1b5187abd54c834b0f8c960.png)