UVA11175 有向图D和E From D to E and Back

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=23&page=show_problem&problem=2116 [PDF](https://uva.onlinejudge.org/external/111/p11175.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11175/faf6823e952ceb9b0051b335e357fb798a5b2407.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11175/4c436af7017003403ad5c0877b9163867151cb60.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11175/988cda0d2792e9b42739c2dc2e4a9c0e4567363a.png)