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;

namespace ConsoleApp1 {
    public class Class1 {
        static void Main(string[] args) {
            int f = int.Parse(Console.ReadLine());
            int[] nums = Console.ReadLine().Trim().Split(' ').Select(_ => int.Parse(_)).ToArray();

            bool b = false;

            for(var i = nums[0]; i <= nums[1]; i++) {
                if(i % f == 0) {
                    b = true;
                    break;
                }
            }

            if (b) {
                Console.Write("OK");
            } else {
                Console.Write("NG");
            }
        }
    }
}