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)

use std;

pub fn main() {
  fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse::<T>().ok().unwrap()
  }
  fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
      .split_whitespace()
      .map(|e| e.parse().ok().unwrap())
      .collect()
  }
  let k = read::<i32>();
  let ab = read_vec::<i32>();
  let a = ab[0];
  let b = ab[1];

  if (k - (a % k)) % k <= b - a {
    println!("OK");
  } else {
    println!("NG");
  }
}