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.Collections.Generic;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        //kの倍数
        int k = int.Parse(Console.ReadLine());
        int[] ab = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray();
        var ans = new List<int>();

    for(var i=ab[0]; i<=ab[1]; i++)
        {
            if (i % k == 0)
            {
                ans.Add(i);
            }
        }

        if (ans.Count() >= 1)
        {
            Console.WriteLine("OK");
        }
        else
        {
            Console.WriteLine("NG");
        }
    }
}