UVA10983 Buy one, get the rest free

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=21&page=show_problem&problem=1924 [PDF](https://uva.onlinejudge.org/external/109/p10983.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10983/e958a67be0f0f2eed2406e8f1c70835bd6c9f3cc.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10983/ebc71de073069ce6edb9a12e454062abbcd77eea.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10983/78a206be5bf5c66e13d9b770ab52e5f590edce5f.png)