// A1Q3.cpp
#include <iostream>
#include <iomanip>
using namespace std;

int GCD (int x, int y);
int main()
{
	int x,y;
	cout << "Enter number of 2 positive integers: ";
	cin >> x >> y;
	if ((x>0)&&(y>0))
		{
			cout << "The greatest common divisor of 2 positive integers is ";
			cout << GCD (x,y) << endl; //call function GCD (x,y);
		}
	else
		cout << "You input (an) invalid integer(s).";
	return 0;
}

int GCD (int x, int y)
{
	int temp,r;
	if (x< y)
		{
			temp=x;
			x=y;
			y=temp;
		}
	r=x%y;
	while(r!=0)
		{
			x=y;
			y=r;
			r=x%y;
		}
	return y;
}