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.*;
public class Main{
    public static void main(String[] args) throws IOException{
        int K;
        String str;
        String[] A = new String[2];
        String ans = "NG";
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        K = Integer.parseInt(r.readLine());
        str = r.readLine();
        A = (str.split(" "));
        for(int i=1;i*K <= Integer.parseInt(A[1]);i++){
            if(Integer.parseInt(A[0]) <= i*K && i*K <= Integer.parseInt(A[1])){
                ans="OK";
                continue;
            }
        }
        System.out.println(ans);
    }
}