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 Rust (1.42.0) (judge verdict: Accepted)

#![allow(dead_code, unused_imports, deprecated)]
use std::cmp::{max, min, Reverse};

use itertools::Itertools;

use maplit::*;

use proconio::{input, fastout};
use proconio::marker::*;

const INF: usize = 1_000_000_007;

#[fastout]
fn solve() {
  input! {
    k: usize,
    a: usize, b: usize,
  };
  
  if a <= b / k * k {
    println!("OK");
  } else {
    println!("NG");
  }
}

fn main() {
  std::thread::Builder::new()
    .name("big stack size".into())
    .stack_size(32 * 1024 * 1024)
    .spawn(|| {
      solve();
    })
    .unwrap()
    .join()
    .unwrap();
}