LOJ 1043

#include<stdio.h>
#include<math.h>
int main()
{
    int T,i;
    scanf("%d",&T);
    for(i=1;i<=T;i++){
        double a,b,c,x;
        scanf("%lf %lf %lf %lf",&a,&b,&c,&x);
        x=sqrt(x/(x+1));
        a=a*x;
        printf("Case %d: %.8lf\n",i,a);
    }
    return 0;
}