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: Wrong Answer)

using System;
using System.Linq;

public class Test
{
	public static void Main()
	{
		// my code goes here
		
		int k = int.Parse(Console.ReadLine());
		var c = Console.ReadLine().Split().Select(x => int.Parse(x)).ToArray();
		int a = c[0];
		int b = c[1];
		int counter = 0;
		for(int i=a;i!=b;i++){
			if(i%k==0){
				counter++;
			}
		}
		
		if(counter==0){
			Console.WriteLine("NG");
		}else{
			Console.WriteLine("OK");
		}
		
	}
}