Problem:
Score: 100 points

Problem Statement

Takahashi the Jumbo will practice golf.

His objective is to get a carry distance that is a multiple of K, while he can only make a carry distance of between A and B (inclusive).

If he can achieve the objective, print OK; if he cannot, print NG.

Constraints

All values in input are integers.

1 \leq A \leq B \leq 1000

1 \leq K \leq 1000

Input

Input is given from Standard Input in the following format:

K
A B

Output

If he can achieve the objective, print OK; if he cannot, print NG.

Sample Input 1

7
500 600

Sample Output 1

OK

Among the multiples of 7, for example, 567 lies between 500 and 600.

Sample Input 2

4
5 7

Sample Output 2

NG

No multiple of 4 lies between 5 and 7.

Sample Input 3

1
11 11

Sample Output 3

OK

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)


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);
	}
 
	
}