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.*;

public class Main {
    public static void main (String[] args) {
        Scanner s = new Scanner(System.in);
          int number = Integer.parseInt(s.next());
        int min = Integer.parseInt(s.next());
        int max = Integer.parseInt(s.next());
          
          if (flag(max, min, number)) System.out.println("OK");
          else System.out.println("NG");
      	
    }

    public static boolean flag (int max, int min, int number) {
        if ((max - min) > number) return true;
        else {
            for (int i = min; i <= max; i++) {
                if (i%number == 0) {
                    return true;
                }
            }
            return false;
          }
    }
}