import java.util.Scanner;
 
public class Main { //クラス名はMain
    public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    }
} import java.util.Scanner; Scanner java.util public class Main { //クラス名はMain
    public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    }
} Main public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    } main {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) int K = in.nextInt(); K in.nextInt() in.nextInt in int A = in.nextInt(); A in.nextInt() in.nextInt in int B = in.nextInt(); B in.nextInt() in.nextInt in if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG"); (B/K - A/K >=1)||(B%K==0)||(A%K==0) (B/K - A/K >=1)||(B%K==0)||(A%K==0) (B/K - A/K >=1) B/K - A/K B/K B K A/K A K 1 (B%K==0) B%K B K 0 (A%K==0) A%K A K 0 System.out.println("OK") System.out.println System.out System System.out "OK" System.out.println("NG") System.out.println System.out System System.out "NG" String[] args args public class Main { //クラス名はMain
    public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    }
} public class Main { //クラス名はMain
    public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    }
} Main
import java.util.Scanner;
 
public class Main { //クラス名はMain
    public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
      int K = in.nextInt();
      int A = in.nextInt();
      int B = in.nextInt();
     
       if ((B/K - A/K >=1)||(B%K==0)||(A%K==0))
            System.out.println("OK");
       else
            System.out.println("NG");
    }
}