###### tags: `CPE`
# *2022/03/22 CPE_02*
## 題目：

#include <iostream>
using namespace std;

int main() {
    int t;
    cin >> t;
    for (int i = 1; i <= t; i++) {
        long long int x0, y0, x1, y1, s0, s1;
        cin >> x0 >> y0 >> x1 >> y1;
        cout << "Case " << i << ": ";
        //The dot before (x0,y0) , include the line of (x0,y0)
        //梯形公式計算(x0,y0)前的座標，x0+1計算 (x0,y0)這斜線前的點，含(x0,y0)
        s0 = (1 + (x0 + y0)) * (x0 + y0) * 1 / 2 + (x0 + 1);
        //The dot before (x1,y1) , include the line of (x1,y1)
        s1 = (1 + (x1 + y1)) * (x1 + y1) * 1 / 2 + (x1 + 1);
        cout << s1 - s0 << endl;
    }
    return 0;
}