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.util.ArrayList;
import java.util.List;
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();
		List<Integer> X = new ArrayList<Integer>();
		List<Integer> Y = new ArrayList<Integer>();
		for(int i = 0; i*K <= B; i++) {
			if(i*K >= A) {
			X.add(i*K);
			}else {
			Y.add(i*K);
			}
		}
		if(X.size()==0) {
			System.out.println("NG");
		}else {
			System.out.println("OK");
		}
	}
}