
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 0) {
            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) {
        Scanner scanner = new Scanner(System.in);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 0) {
            System.out.println("OK");
        } else {
            System.out.println("NG");
        }
    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 0) {
            System.out.println("OK");
        } else {
            System.out.println("NG");
        }
    } main {
        Scanner scanner = new Scanner(System.in);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 0) {
            System.out.println("OK");
        } else {
            System.out.println("NG");
        }
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int K = scanner.nextInt(); K scanner.nextInt() scanner.nextInt scanner int A = scanner.nextInt(); A scanner.nextInt() scanner.nextInt scanner int B = scanner.nextInt(); B scanner.nextInt() scanner.nextInt scanner if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        } A % K == 0 || B % K == 0 A % K == 0 A % K A K 0 B % K == 0 B % K B K 0 {
            System.out.println("OK");
            return;
        } System.out.println("OK") System.out.println System.out System System.out "OK" return; int a = A / K; a A / K A K int b = B / K; b B / K B K if (b - a > 0) {
            System.out.println("OK");
        } else {
            System.out.println("NG");
        } b - a > 0 b - a b a 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);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 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);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 0) {
            System.out.println("OK");
        } else {
            System.out.println("NG");
        }
    }
} Main

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int K = scanner.nextInt();
        int A = scanner.nextInt();
        int B = scanner.nextInt();

        if (A % K == 0 || B % K == 0) {
            System.out.println("OK");
            return;
        }

        int a = A / K;
        int b = B / K;
        if (b - a > 0) {
            System.out.println("OK");
        } else {
            System.out.println("NG");
        }
    }
}
