#include<bits/stdc++.h>

using namespace std;

void solve(int t) {
    int r1, r2, h, p; cin >> r1 >> r2 >> h >> p;
    double r = r1 - ((r1 - r2) / h * (h - p));
    double x = (r1 * h) / (r1 - r2);

    double ans = (acos(-1) / 3) * ((r * r * (x - h + p)) - (r2 * r2 * (x - h)));
    printf("Case %d: %0.9f\n", t, ans);

}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int T = 1; cin >> T;
    for (int i = 1; i <= T; i++) {
        solve(i);
    }
}