Tutorial for the problem : http://light-online-judge.blogspot.com/search?q=1216

/*
Link: http://www.lightoj.com/volume_showproblem.php?problem=1216
*/

#include <bits/stdc++.h>

#define pii pair <int,int>
#define sc scanf
#define pf printf
#define Pi 2*acos(0.0)
#define ms(a,b) memset(a, b, sizeof(a))
#define pb(a) push_back(a)
#define MP make_pair
#define oo 1<<29
#define dd double
#define ll long long
#define EPS 10E-10
#define ff first
#define ss second
#define MAX 10000
#define SZ(a) (int)a.size()
#define getint(a) scanf("%d",&a)
#define loop(i,n) for(int i=0;i<n;i++)
#define TEST_CASE(t) for(int z=1;z<=t;z++)
#define PRINT_CASE printf("Case %d: ",z)
#define all(a) a.begin(),a.end()
#define intlim 2147483648
#define inf 1000000
#define rtintlim 46340
#define llim 9223372036854775808
#define rtllim 3037000499
#define ull unsigned long long
#define I int

using namespace std;

int main()
{
    ///freopen("in.txt","r",stdin);
    ///freopen("out.txt","w",stdout);

    int t;
    cin>>t;
    TEST_CASE(t)
    {
        int r1,r2,h,p;
        cin>>r1>>r2>>h>>p;
        double p_r = r2+(r1-r2)*(double)p/h*1.0;
        double ans = 1.0/3*Pi*p*(p_r*p_r+r2*r2*1.0+p_r*r2);
        PRINT_CASE;
        pf("%lf\n",ans);
    }
    return 0;
}