#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;
using u128 = unsigned __int128;

using F = double;

void solve() {
    int h1, w1, h2, w2;
    std::cin >> h1 >> w1 >> h2 >> w2;
    
    F ans = INFINITY;
    
    auto check = [&](int a, int b, int c, int d) {
        ans = std::min(ans, 1.0 * (b + d) * std::min(a, c) + 1.0 * (b + d + (a > c ? b : d)) * std::abs(a - c) / 2);
    };
    
    check(h1, w1, h2, w2);
    check(h1, w1, w2, h2);
    check(w1, h1, h2, w2);
    check(w1, h1, w2, h2);
    
    std::cout << ans << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    std::cout << std::fixed << std::setprecision(10);
    
    int t;
    std::cin >> t;
    
    for (int i = 1; i <= t; i++) {
        std::cout << "Case " << i << ": ";
        solve();
    }
    
    return 0;
}