UVA501 Black Box

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=7&page=show_problem&problem=442 [PDF](https://uva.onlinejudge.org/external/5/p501.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA501/794b727ccb5ae482ad64212b50510c376fee2c00.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA501/22341cc0cdd3d3aa9d0c86c70a624c5a02117097.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA501/7b4826284c0211aac4098a4fcc19e73f1d9717fc.png)