import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		if(n / m > 1000) {
			System.out.println(n / m / 1000 * 1000);
		} else {
			System.out.println(0);
		}
	}
}