UVA11320 Hidden Triangles

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=25&page=show_problem&problem=2295 [PDF](https://uva.onlinejudge.org/external/113/p11320.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11320/76492257e61da39a8bf578f8008e5ac8f432b85a.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11320/c8e694ba4aa45ee657d9610c8c9be56ee34337fa.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11320/49d62647954fed0315055445f26fc3c06996a275.png)