import java.util.Scanner;
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner koko = new Scanner(System.in);
        long n = koko.nextLong();
        int m = koko.nextInt();
        long modn = n%1000;
        long total = (n-modn)/1000;
        long modt = total%m;
        long h = (total-modt)/m;
        System.out.println(h*1000);
    }
}