飞机环球 Planes around the World

题目描述

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=18&page=show_problem&problem=1581 [PDF](https://uva.onlinejudge.org/external/106/p10640.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10640/e6039ea048a198558d7dfa489be596425bc9bda8.png)

输入输出格式

输入格式


![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10640/8490eb331c01f5cd52411da9f9040df895e8caff.png)

输出格式


![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA10640/8c9357202122f22b930a771f58b830a03971513e.png)

输入输出样例

输入样例 #1

3
1 2
1 3
2 5

输出样例 #1

Case 1: 5
Case 2: -1
Case 3: 13