import static java.lang.System.*;
import java.util.Scanner;
public class No446{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		String A=sc.nextLine();
		String B=sc.nextLine();
		try{
			int a=Integer.parseInt(A);
			int b=Integer.parseInt(B);
			if(check(a)==1&&check(b)==1){
				out.println("OK");
			}else{
				out.println("NG");
			}
		}catch(Exception e){
			out.println("NG");
		}
	}
	private static int check(int i){
		if(0<=i&&i<=12345){return 1;}
		else{return 0;}
	}
}