fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let n: Vec<u64> = s.split_whitespace().flat_map(str::parse).collect();
	let mut a = 1000;
	for i in n[0]..=n[1].min(n[0] + 999) {
		a = a.min((1000 - i * n[2] % 1000) % 1000);
	}
	println!("{a}")
}