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.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.stream.*;
import java.util.concurrent.*;
import java.util.regex.*;
import java.util.function.*;
import static java.lang.System.out;


public final class Main {
	public static void main(String[] args) throws IOException {
		try (var istr = new InputStreamReader(System.in);
			 var br = new BufferedReader(istr)) {
			int k = Integer.parseInt(br.readLine());
			var st = new StringTokenizer(br.readLine());
			int a = Integer.parseInt(st.nextToken());
			int b = Integer.parseInt(st.nextToken());
			for (int score = a; score <= b; score++) {
				if (score % k == 0) {
					out.printf("OK%n");
					return;
				}
			}
			out.printf("NG%n");
		}
	}
}