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)

//package beg_165;
import java.util.*;
public class Main {

	public static void main(String[] args) {
		Scanner a = new Scanner(System.in);
		int b = a.nextInt();
		String xdrtcfvygbuh = a.nextLine();
		
		String c = a.nextLine();
		String[] list = c.split(" ");
		
		int f = Integer.parseInt(list[0]);
		int l = Integer.parseInt(list[1]);
		boolean check=true;
		for (int i=f;i<=l;i++) {
			if (i%b==0) {
				System.out.println("OK");
				
				check=false;
				break;
			}
		}
		if (check) {
			System.out.println("NG");
		}

	}

}