Алгоритм Евкліда 4-x чисел

C++

#include "stdafx.h"
#include <iostream>

using namespace std;

int NOD(int a, int b) {
	if (a == 0) {
		return b; 
	}
	
	while ((b != a) && (b != 0)) {
		if (a > b) {
			a -= b;
		} else {
			b -= a;
		}
	}
	
	return a;
}

int main() {
	int a, b, c, d, firstNod, secondNod;
	cout << "A=";
	cin >> a;
	cout << "B=";
	cin >> b;
	cout << "C=";
	cin >> c;
	cout << "D=";
	cin >> d;

	firstNod = NOD(a, b);
	cout << "First NOD=" << firstNod << endl;
	
	secondNod = NOD(c, d);
	cout << "Second NOD=" << secondNod << endl;
	
	cout << "Absolute NOD=" << NOD(firstNod, secondNod) << endl;

	system("pause");
	return 0;
}