UVA11903 e-Friends

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=229&page=show_problem&problem=3054 [PDF](https://uva.onlinejudge.org/external/119/p11903.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11903/e83412fd108ff98e9795ca384377ddda9cb19555.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11903/537e5d2e101a7074d2e2df8dfdefcf8923db1f85.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11903/edfb7a0e33eb8da53918d83d6b8c82858a38efaf.png)