package P128;

import java.util.Scanner;

public class P128 {
	public static void main(String args[]){
		
		Scanner sc = new Scanner(System.in);
		String n = sc.nextLine();
		double nd = Double.parseDouble(n);
		String m = sc.nextLine();
		double md = Double.parseDouble(m);
		
		double sheet = Math.floor(nd/1000);
		double ans;
		ans = 1000*((sheet-(sheet%md))/md);
		System.out.printf("%.0f",ans);
	}
	
}