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);

    let mut min = 2000;

    for x in l..=r {
        let mut b = 1000 - ((c * x) % 1000);
        if b == 1000 {
            b = 0;
        }

        if b < min {
            min = b;
        }
    }

    println!("{min}");
}