import java.util.Scanner;
import java.util.Arrays;
import java.util.List;

public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	}
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util import java.util.List; List java.util public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	}
} Main public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	} main {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int input = Integer.parseInt(sc.nextLine()); input Integer.parseInt(sc.nextLine()) Integer.parseInt Integer sc.nextLine() sc.nextLine sc String[] array = sc.nextLine().split(" "); array sc.nextLine().split(" ") sc.nextLine().split sc.nextLine() sc.nextLine sc " " int min = Integer.parseInt(array[0]); min Integer.parseInt(array[0]) Integer.parseInt Integer array[0] array 0 int max = Integer.parseInt(array[1]); max Integer.parseInt(array[1]) Integer.parseInt Integer array[1] array 1 String result = max/input*input >= min ? "OK" : "NG"; result max/input*input >= min ? "OK" : "NG" max/input*input >= min max/input*input max/input max input input min "OK" "NG" System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	}
} public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	}
} Main
import java.util.Scanner;
import java.util.Arrays;
import java.util.List;

public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
	    int input = Integer.parseInt(sc.nextLine());
		String[] array = sc.nextLine().split(" ");
		int min = Integer.parseInt(array[0]);
		int max = Integer.parseInt(array[1]);
		String result = max/input*input >= min ? "OK" : "NG";
	    System.out.println(result);
	}
}
