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: Wrong Answer)

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int k = sc.nextInt();
        int a = sc.nextInt();
        int b = sc.nextInt();
        if(k > b){
            System.out.println("NG");
            System.exit(0);
        }
        if(b > k || k> a){
            System.out.println("OK");
            System.exit(0);
        }
        if(b-a < k){
            if(a == b){
                if(a%k == 0){
                    System.out.println("OK");
                    System.exit(0);
                }
                else{
                    System.out.println("NG");
                    System.exit(0);
                }
            }
            System.out.println("NG");
        }
        else{
            System.out.println("OK");
        }
    }
}