import java.io.*;

class GCD
{
// Prompts for two numbers and gives their greatest common divisor
// (iterative version)

 public static void main(String[] args) throws IOException
 {
  int m,n,rem;
  BufferedReader in = Text.open(System.in);
  System.out.print("Enter two numbers: ");
  m=Text.readInt(in);
  n=Text.readInt(in);
  while(n!=0)
     {
      rem=m%n;
      m=n;
      n=rem;
     }
  System.out.println("Greatest common divisor: "+m);
 }

}