1 /**************************************************************
 2     Problem: 3093
 3     User: Tunix
 4     Language: C++
 5     Result: Accepted
 6     Time:0 ms
 7     Memory:804 kb
 8 ****************************************************************/
 9  
10 //BZOJ 3093
11 #include<cstdio>
12 int main(){
13     int n,p,q,t=0;
14     while(scanf("%d%d%d",&n,&p,&q)!=EOF)
15         printf("Case %d: %.4f\n",++t,(q+1.0)/(p+2.0));
16     return 0;
17 }