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 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        //コード
    	Scanner sc = new Scanner(System.in);
//    	File file = new File("src/in.txt");
//    	Scanner sc = new Scanner(file);
    	int K = sc.nextInt();
    	int A = sc.nextInt();
    	int B = sc.nextInt();
    	boolean result = false;

    	for(int i=A;i<=B;i++) {
    		if(i%K==0) {
    			result = true;
    			break;
    		}
    	}
    	if(result) {
    		System.out.println("OK");
    	} else {
    		System.out.println("NG");
    	}

    }
}