import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();

		a = a /1000;
		if(a < b){
			System.out.println("0");
		}else{
			System.out.println(a/b*1000);
		}
	}
}