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

public class Main {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  }
} Main public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  } main {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) final int k = scanner.nextInt(); k scanner.nextInt() scanner.nextInt scanner final int a = scanner.nextInt(); a scanner.nextInt() scanner.nextInt scanner final int b = scanner.nextInt(); b scanner.nextInt() scanner.nextInt scanner if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    } k * (a / k + 1) <= b || a % k == 0 k * (a / k + 1) <= b k * (a / k + 1) k (a / k + 1) a / k a k 1 b a % k == 0 a % k a k 0 {
      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) {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  }
} public class Main {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  }
} Main

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

public class Main {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    final int k = scanner.nextInt();
    final int a = scanner.nextInt();
    final int b = scanner.nextInt();

    if (k * (a / k + 1) <= b || a % k == 0) {
      System.out.println("OK");
    } else {
      System.out.println("NG");
    }

  }
}
