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 C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;


class Program
{
    static void Main(string[] args)
    {
        int K = int.Parse(Console.ReadLine());
        string[] AB = Console.ReadLine().Split(' ');
        int A = int.Parse(AB[0]);
        int B = int.Parse(AB[1]);

        string answer = "NG";
        for(int i=A; i<=B; i++){
            if(i%K == 0){
                answer = "OK";
            }
        }
        Console.WriteLine(answer);
    }
}