import java.util.Scanner;

public class MyMain {

	final static String YUKICODER = "yukicoder";

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		long l = Long.parseLong(sc.nextLine());
		long r = Long.parseLong(sc.nextLine());
		long c = Long.parseLong(sc.nextLine());
		final long y = 1000;

		long x = y / c;

		System.out.println((x >= l && x <= r) ? y - (c * x) : y - (c * r));

		sc.close();
	}
}