Masud Rana

题目描述

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=78&page=show_problem&problem=2647 [PDF](https://uva.onlinejudge.org/external/116/p11600.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11600/21a6272c6c60df9f610e67035292a7fb3a80d21d.png)

输入输出格式

输入格式


![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11600/8ab5bad9e50d982eaf10e3103b7f448a01970d50.png)

输出格式


![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA11600/fd3348f79ae1e772e49173e56f782418b18668db.png)

输入输出样例

输入样例 #1

2
3 1
2 3
4 1
2 3

输出样例 #1

Case 1: 1.0
Case 2: 3.5