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;
class p
{
  static void Main()
  {
    int K = int.Parse(Console.ReadLine());
    string[] ipt = Console.ReadLine().Split(' ');
    int A = int.Parse(ipt[0]);
    int B = int.Parse(ipt[1]);
    bool result = false;
    for (int i = A; i <= B; i++) {
      if (i % K == 0) {
        result = true;
        break;
      }
    }
    Console.WriteLine(result ? "OK" : "NG");
  }
}