//CS5-HMC-Sp.,00-HW13-2
//A. Khakpour, May,00

class Euclid
{
   public static void main (String[] args)
   {
      int a, b;
      System.out.print("Enter the first positive integer: ");
      a = Keyboard.readInt();
      System.out.print("Enter the second positive integer: ");
      b = Keyboard.readInt();
      int c = DivisorCalc.gcd(a, b);
      System.out.println("The greatest commmon divisor is: " + c);
   }
}

class DivisorCalc
{
   public static int gcd(int num1, int num2)
   {
      if (num2 <= num1 && num1 % num2 == 0)
         return num2;
      else if (num1 < num2)
         return gcd(num2, num1);
      else
         return gcd(num2, num1 % num2);
   }
}