UVA398 18-Wheeler Caravans (aka Semigroups)

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=5&page=show_problem&problem=334 [PDF](https://uva.onlinejudge.org/external/3/p398.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA398/181ffcd66fa51b2a030016ea525cf3601bd4c37b.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA398/8d7d740384734cff13ba22548fcbede5c9fcba65.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA398/42ac1b5e16943285d359195e6daefa0d20b52e70.png)