import java.util.*;
import java.io.*;

public class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in), 32768);
    static PrintWriter out = new PrintWriter(System.out);
    static StringTokenizer t;

    static String sn() {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    }

    static int ni() {
        return Integer.parseInt(sn());
    }

    static long nlo() {
        return Long.parseLong(sn());
    }

    public static void main(String args[]) {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    }

    static long mod = (long) 1e9 + 7;

    static long pro(long a, long b) {
        return (a % mod * b % mod) % mod;
    }

    static int maxn = 100005;

    static class sort implements Comparator<String> {
        public int compare(String a, String b) {
            return a.length() - b.length();
        }
    }

    static void solve() {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    }
} import java.util.*; util.* java import java.io.*; io.* java public class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in), 32768);
    static PrintWriter out = new PrintWriter(System.out);
    static StringTokenizer t;

    static String sn() {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    }

    static int ni() {
        return Integer.parseInt(sn());
    }

    static long nlo() {
        return Long.parseLong(sn());
    }

    public static void main(String args[]) {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    }

    static long mod = (long) 1e9 + 7;

    static long pro(long a, long b) {
        return (a % mod * b % mod) % mod;
    }

    static int maxn = 100005;

    static class sort implements Comparator<String> {
        public int compare(String a, String b) {
            return a.length() - b.length();
        }
    }

    static void solve() {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    }
} Main static BufferedReader br = new BufferedReader(new InputStreamReader(System.in), 32768); br new BufferedReader(new InputStreamReader(System.in), 32768) static PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) static StringTokenizer t; t static long mod = (long) 1e9 + 7; mod (long) 1e9 + 7 (long) 1e9 7 static int maxn = 100005; maxn 100005 static String sn() {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    } sn {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    } while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        } t == null || !t.hasMoreTokens() t == null t null !t.hasMoreTokens() t.hasMoreTokens() t.hasMoreTokens t {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        } try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            } catch (IOException e) {
                throw new RuntimeException();
            } IOException e {
                throw new RuntimeException();
            } throw new RuntimeException(); new RuntimeException() {
                t = new StringTokenizer(br.readLine());
            } t = new StringTokenizer(br.readLine()) t new StringTokenizer(br.readLine()) return t.nextToken(); t.nextToken() t.nextToken t static int ni() {
        return Integer.parseInt(sn());
    } ni {
        return Integer.parseInt(sn());
    } return Integer.parseInt(sn()); Integer.parseInt(sn()) Integer.parseInt Integer sn() sn static long nlo() {
        return Long.parseLong(sn());
    } nlo {
        return Long.parseLong(sn());
    } return Long.parseLong(sn()); Long.parseLong(sn()) Long.parseLong Long sn() sn public static void main(String args[]) {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    } main {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    } int t = 1; t 1 while (t-- > 0) {
            solve();
        } t-- > 0 t-- t 0 {
            solve();
        } solve() solve out.close() out.close out String args[] args static long pro(long a, long b) {
        return (a % mod * b % mod) % mod;
    } pro {
        return (a % mod * b % mod) % mod;
    } return (a % mod * b % mod) % mod; (a % mod * b % mod) % mod (a % mod * b % mod) a % mod * b a % mod a mod b mod mod long a a long b b static void solve() {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    } solve {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    } int k = ni(); k ni() ni int a = ni(); a ni() ni int b = ni(); b ni() ni int f = 0; f 0 for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        } int i = a; int i = a; i a i <= b i b i++ i++ i {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        } {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        } if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            } i % k == 0 i % k i k 0 {
                f = 1;
                out.println("OK");
                break;
            } f = 1 f 1 out.println("OK") out.println out "OK" break; if (f == 0) {
            out.println("NG");
        } f == 0 f 0 {
            out.println("NG");
        } out.println("NG") out.println out "NG" static class sort implements Comparator<String> {
        public int compare(String a, String b) {
            return a.length() - b.length();
        }
    } sort public int compare(String a, String b) {
            return a.length() - b.length();
        } compare {
            return a.length() - b.length();
        } return a.length() - b.length(); a.length() - b.length() a.length() a.length a b.length() b.length b String a a String b b Comparator public class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in), 32768);
    static PrintWriter out = new PrintWriter(System.out);
    static StringTokenizer t;

    static String sn() {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    }

    static int ni() {
        return Integer.parseInt(sn());
    }

    static long nlo() {
        return Long.parseLong(sn());
    }

    public static void main(String args[]) {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    }

    static long mod = (long) 1e9 + 7;

    static long pro(long a, long b) {
        return (a % mod * b % mod) % mod;
    }

    static int maxn = 100005;

    static class sort implements Comparator<String> {
        public int compare(String a, String b) {
            return a.length() - b.length();
        }
    }

    static void solve() {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    }
} public class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in), 32768);
    static PrintWriter out = new PrintWriter(System.out);
    static StringTokenizer t;

    static String sn() {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    }

    static int ni() {
        return Integer.parseInt(sn());
    }

    static long nlo() {
        return Long.parseLong(sn());
    }

    public static void main(String args[]) {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    }

    static long mod = (long) 1e9 + 7;

    static long pro(long a, long b) {
        return (a % mod * b % mod) % mod;
    }

    static int maxn = 100005;

    static class sort implements Comparator<String> {
        public int compare(String a, String b) {
            return a.length() - b.length();
        }
    }

    static void solve() {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    }
} Main
import java.util.*;
import java.io.*;

public class Main {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in), 32768);
    static PrintWriter out = new PrintWriter(System.out);
    static StringTokenizer t;

    static String sn() {
        while (t == null || !t.hasMoreTokens()) {
            try {
                t = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return t.nextToken();
    }

    static int ni() {
        return Integer.parseInt(sn());
    }

    static long nlo() {
        return Long.parseLong(sn());
    }

    public static void main(String args[]) {
        int t = 1;//ni();
        while (t-- > 0) {
            solve();
        }
        out.close();
    }

    static long mod = (long) 1e9 + 7;

    static long pro(long a, long b) {
        return (a % mod * b % mod) % mod;
    }

    static int maxn = 100005;

    static class sort implements Comparator<String> {
        public int compare(String a, String b) {
            return a.length() - b.length();
        }
    }

    static void solve() {
        int k = ni();
        int a = ni();
        int b = ni();
        int f = 0;
        for (int i = a; i <= b; i++) {
            if (i % k == 0) {
                f = 1;
                out.println("OK");
                break;
            }
        }
        if (f == 0) {
            out.println("NG");
        }
    }
}