10642 - Can You Solve It?

#include <iostream>
#include <string>
#include <iomanip>
#include <cmath>
#include<sstream>
using namespace std;

int main()
{
	int t, c = 1;
	cin >> t;
	while (t--) {
		int x1, x2, y1, y2;
		cin >> x1 >> y1 >> x2 >> y2;
		int count = 0;
		count += (x2 + y2 + x1 + y1 + 1) * (x2 + y2 - x1 - y1) / 2;
		count += (x2 - x1);
		cout << "Case " << c << ": " << count << endl;
	}
}