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)

struct Rin{}
impl Rin{
    fn input(&self)->String{
        let mut x=String::new();
        std::io::stdin().read_line(&mut x).ok();
        x
    }
    fn inputs(&self)->String{
        let s=self.input().trim().to_string();
        s
    }
    fn inputn(&self)->i32{
        let n:i32=self.input().trim().parse().unwrap();
        n
    }
    fn inputvs(&self)->Vec<String>{
        let vs=self.input().trim().split(' ').map(|x|x.to_string()).collect();
        vs
    }
    fn inputvn(&self)->Vec<i32>{
        let vn=self.input().trim().split(' ').map(|x|x.to_string().parse().unwrap()).collect();
        vn
    }
}

fn main(){
    let r=Rin{};
    let k=r.inputn();
    let v=r.inputvn();
    let a=v[0];
    let b=v[1];
    if a<=b/k*k{
        println!("OK");
    }else{
        println!("NG");
    }
}