import java.math.BigInteger;
public class GcdProg
{
public static void main(String[] args)
  {
  BigInteger x = new BigInteger(args[0]);	// constructor
  BigInteger y = new BigInteger(args[1]);
//  System.out.println("args.length " + args.length);
  BigInteger z; // = new BigInteger("0");

  z = x.gcd(y);
  System.out.println(z.toString(10));
  }
}