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.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();

        boolean ok = false;
        if(a %k ==0 || b%k == 0) ok = true;
        if(!ok){
            int r = a % k;
            int temp = a- r;
            for(int i=temp; i<b; i+=k){
                if(i > a && i%k == 0){
                    ok = true;
                    break;
                }
            }

        }
        if(ok) System.out.println("OK");
        else System.out.println("NG");
    }
}