//uva10642 #include <iostream> #define ll long long int using namespace std; void solve(int i) { long long int x0, y0, x1, y1, s0, s1; cin >> x0 >> y0 >> x1 >> y1; cout << "Case " << i << ": "; s0 = x0 + y0 + (x0 + y0 - 1) * (x0 + y0) / 2 + x0; s1 = x1 + y1 + (x1 + y1 - 1) * (x1 + y1) / 2 + x1; cout << s1 - s0 << endl; } int main() { int t; cin >> t; for (int i = 1; i <= t; i++) { solve(i); } return 0; }