
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;



public class Main {

	public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	}
 
//	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[];
	static int[] ar;
	static Scanner sc = new Scanner(System.in);
	static int pri[] = new int[(int) 1e6 + 5];
	static StringBuilder out = new StringBuilder();
 
	//static long dp[];
 
	public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	}
 
	
} import java.io.IOException; IOException java.io import java.util.ArrayList; ArrayList java.util import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

	public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	}
 
//	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[];
	static int[] ar;
	static Scanner sc = new Scanner(System.in);
	static int pri[] = new int[(int) 1e6 + 5];
	static StringBuilder out = new StringBuilder();
 
	//static long dp[];
 
	public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	}
 
	
} Main //	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[]; gr static int[] ar; ar static Scanner sc = new Scanner(System.in); sc new Scanner(System.in) static int pri[] = new int[(int) 1e6 + 5]; pri new int[(int) 1e6 + 5] (int) 1e6 + 5 (int) 1e6 5 static StringBuilder out = new StringBuilder(); out new StringBuilder() public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	} main {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	} int t =1; t 1 while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		} t-- > 0 t-- t 0 {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		} int n=sc.nextInt(); n sc.nextInt() sc.nextInt sc int a=sc.nextInt(); a sc.nextInt() sc.nextInt sc int b=sc.nextInt(); b sc.nextInt() sc.nextInt sc if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			} a%n==0 || b%n==0 a%n==0 a%n a n 0 b%n==0 b%n b n 0 {
				out.append("OK\n");
				continue;
			} out.append("OK\n") out.append out "OK\n" continue; if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			} a/n!=b/n a/n a n b/n b n {
				out.append("OK\n");
				continue;
			} out.append("OK\n") out.append out "OK\n" continue; out.append("NG\n") out.append out "NG\n" System.out.println(out) System.out.println System.out System System.out out String[] args args public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	} pair int id; id int ans; ans pair(int x, int y) {
 
			id = x;
			ans = y;
 
		} pair {
 
			id = x;
			ans = y;
 
		} id = x id x ans = y ans y int x x int y y public pair() {
 
		} pair {
 
		} public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		} compareTo {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		} return this.id - o.id; this.id - o.id this.id this this.id o.id o o.id pair o o Comparable public class Main {

	public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	}
 
//	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[];
	static int[] ar;
	static Scanner sc = new Scanner(System.in);
	static int pri[] = new int[(int) 1e6 + 5];
	static StringBuilder out = new StringBuilder();
 
	//static long dp[];
 
	public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	}
 
	
} public class Main {

	public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	}
 
//	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[];
	static int[] ar;
	static Scanner sc = new Scanner(System.in);
	static int pri[] = new int[(int) 1e6 + 5];
	static StringBuilder out = new StringBuilder();
 
	//static long dp[];
 
	public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	}
 
	
} Main

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;



public class Main {

	public static class pair implements Comparable<pair> {
		int id;
		int ans;
 
		pair(int x, int y) {
 
			id = x;
			ans = y;
 
		}
 
		public pair() {
 
		}
 
		public int compareTo(pair o) {
			// TODO Auto-generated method stub
 
			return this.id - o.id;
		}
	}
 
//	static int mod = (int) 998244353.;
	static ArrayList<Integer> gr[];
	static int[] ar;
	static Scanner sc = new Scanner(System.in);
	static int pri[] = new int[(int) 1e6 + 5];
	static StringBuilder out = new StringBuilder();
 
	//static long dp[];
 
	public static void main(String[] args) throws IOException {
		int t =1;//sc.nextInt();
		
		while (t-- > 0) {
 
			int n=sc.nextInt();
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a%n==0 || b%n==0) {
				out.append("OK\n");
				continue;
			}
			if(a/n!=b/n ) {
				out.append("OK\n");
				continue;
			}
			out.append("NG\n");
			

		
		}
		
		System.out.println(out);
	}
 
	
}