import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		try {
			Scanner scan = new Scanner(System.in);
			int N = scan.nextInt();
			int M = scan.nextInt();

			int ans = N / M / 1000 * 1000;

			System.out.println(ans);

			scan.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}