import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    }
} Main public static void main(String[] args) {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    } main {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    } boolean isOk = false; isOk false Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int target = Integer.parseInt(sc.next()); target Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int minDistance = sc.nextInt(); minDistance sc.nextInt() sc.nextInt sc int maxDistance = sc.nextInt(); maxDistance sc.nextInt() sc.nextInt sc for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        } int i=minDistance; int i=minDistance; i minDistance i <= maxDistance i maxDistance i++ i++ i {
            if (i%target == 0){
                isOk = true;
                break;
            }
        } {
            if (i%target == 0){
                isOk = true;
                break;
            }
        } if (i%target == 0){
                isOk = true;
                break;
            } i%target == 0 i%target i target 0 {
                isOk = true;
                break;
            } isOk = true isOk true break; if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        } isOk {
            System.out.println("OK");
        } System.out.println("OK") System.out.println System.out System System.out "OK" {
            System.out.println("NG");
        } System.out.println("NG") System.out.println System.out System System.out "NG" String[] args args public class Main {
    public static void main(String[] args) {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    }
} public class Main {
    public static void main(String[] args) {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        boolean isOk = false;

        Scanner sc = new Scanner(System.in);
        int target = Integer.parseInt(sc.next());
        int minDistance = sc.nextInt();
        int maxDistance = sc.nextInt();

        for (int i=minDistance;i <= maxDistance;i++){
            if (i%target == 0){
                isOk = true;
                break;
            }
        }
        if(isOk){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
    }
}
