过河 Crossing Rivers
题目描述
[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=244&page=show_problem&problem=3382
[PDF](https://uva.onlinejudge.org/external/122/p12230.pdf)
![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12230/b612c63e18559127bd3e854aaaeb5bcd863c134d.png)
输入输出格式
输入格式
![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12230/56253f5b6e8906f830ef43cf2037f78e517ddedc.png)
输出格式
![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12230/9be4ff92b94be5587ca0487cbf72ef3c509536dc.png)
输入输出样例
输入样例 #1
1 1
0 1 2
0 1
0 0
输出样例 #1
Case 1: 1.000
Case 2: 1.000