UVA12789 Space Invaders

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=823&page=show_problem&problem=4654 [PDF](https://uva.onlinejudge.org/external/127/p12789.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12789/841081b6fbc04252a84b2fe942095e817c90d98f.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12789/7ac6b8b68882dd6260b1eca540fe57524d8802bf.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12789/f1a74d13a6347c276ef7369f523e1ce616a5ba02.png)