macro_rules! scan_iter {
    ($buf:expr) => {{
        use std::io::{stdin, BufRead};
        use std::str::FromStr;

        $buf.clear();
        stdin().lock().read_line(&mut $buf).unwrap();
        $buf.trim()
            .split(" ")
            .map(|x| FromStr::from_str(x).unwrap())
    }};
}

macro_rules! scan_vec {
    ($buf:expr) => {
        scan_iter!($buf).collect::<Vec<_>>()
    };
}

macro_rules! scan_into {
    ($buf:expr) => {
        scan_vec!($buf).try_into().unwrap()
    };
}

fn main() {
    let mut b = String::new();
    let [l, r, c]: [i32; 3] = scan_into!(b);

    println!(
        "{}",
        (l..=r)
            .map(|x| match 1000 - (c * x) % 1000 {
                1000 => 0,
                y => y,
            })
            .min()
            .unwrap()
    );
}