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::io::*;

fn main() {
    let mut buf = String::new();
    stdin().read_to_string(&mut buf).unwrap();

    let (k, a, b) = match &buf
        .split_whitespace()
        .map(|x| x.parse().unwrap())
        .collect::<Vec<i64>>()[..]
    {
        &[k, a, b] => (k, a, b),
        _ => panic!(),
    };

    println!("{}", if b / k * k >= a { "OK" } else { "NG" });
}