import java.io.IOException;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws NumberFormatException, IOException{

		Scanner sc = new Scanner(System.in);
		long numA = sc.nextLong();
		long numB = sc.nextLong();
		long numC = (numA/(numB*1000))*1000;
		System.out.println(numC);
	}
}