Greatest Common Divisor 2

#include <iostream>
using namespace std;

int GCD(int a, int b)
{
    while( 1 )
    {
        a = a % b;
  if( a == 0 )
   return b;
  b = b % a;

        if( b == 0 )
   return a;
    }
}

int main()
{
 int x, y;

 cout << "This program allows calculating the GCD\n";
 cout << "Value 1: ";
 cin >> x;
 cout << "Value 2: ";
 cin >> y;

 cout << "\nThe Greatest Common Divisor of "
      << x << " and " << y << " is " << GCD(x, y) << endl;  

 return 0;
}