package no446;

import java.util.Scanner;
import java.util.regex.Pattern;

public class Main {

	public static Pattern regex = Pattern.compile("(0|[1-9][0-9]*)");
	public static int MAX = 12345;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = parse(sc.next());
		int b = parse(sc.next());
		if (0 <= a && a <= MAX && 0 <= b && b <= MAX) {
			System.out.println("OK");
		}else{
			System.out.println("NG");
		}
	}
	
	public static int parse(String s) {
		if (regex.matcher(s).matches()) {
			return Integer.parseInt(s);
		}else{
			return -1;
		}
	}

}