UVA12426 Counting Triangles

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=279&page=show_problem&problem=3857 [PDF](https://uva.onlinejudge.org/external/124/p12426.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12426/f8e81d99e8e4caaf6ebeac6c4dd2f69d78e885a5.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12426/23f9e201be5070f966ce090e249bd487fef17684.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12426/491ba6a333216f449d268ad2319e91461d5d5565.png)