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# (Mono-mcs 6.8.0.105) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
class abc165_a{
  public static void Main(){
    int k = int.Parse(Console.ReadLine());
    bool flag = false;
    int[] range = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
    for(int i=range[0]; i<=range[1] && !flag; i++){
      if(i%k == 0){
        flag = true;
      }
    }
    if(flag)
      Console.WriteLine("OK");
    else
      Console.WriteLine("NG");
  }
}