UVA10564 Paths through the Hourglass

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=17&page=show_problem&problem=1505 [PDF](https://uva.onlinejudge.org/external/105/p10564.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10564/b9d25f86be98e4accb4fd0ce15c0cfef95b3c3cd.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10564/60ff679a3bfd0484f7486277e2495cd8efa7ac8b.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10564/f9a02f2e10b38d54034366442ad831a00c7b4629.png)