UVA12562 In an effort to Change History

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=441&page=show_problem&problem=4007 [PDF](https://uva.onlinejudge.org/external/125/p12562.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12562/23fa79a829bad41bafca0acca3fe7307c3fdc90a.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12562/d64c104223feeedc5c8d8fc62a1c05eff1bf9d40.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12562/a44d5d26238de395b9901cbfd94932dcc0de8135.png)