#include <iostream>
#include <math.h>
using namespace std;

int main()
{
	double a,b,c,d,divAC,divBD;
	cout << "Input number for a,b,c,d:" << endl;
	cin >> a >> b >> c >> d;
	divAC = abs(a - c);
	divBD = abs(b - d);
	if (divAC == divBD) {
		cout << "D";
	}
	if (divAC == 0) {
		cout << "V";
	}
	if (divBD == 0) {
		cout << "G";
	}
	else {
		cout << "CORRECT" << endl;
	}
	system("pause");
	return 0;

}