package yukicoder128;
import java.util.Scanner;
public class yukicoder128 {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		n=n/1000;
		int m=sc.nextInt();
		System.out.println(((int)(n/m))*1000);
	}
}