package j_25;

import java.util.Scanner;

public class FizzBuzz {
public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	long N = sc.nextLong();
	int M = sc.nextInt();
	sc.close();
		long O = (N / (M * 1000)) * 1000;
		System.out.println(O);
	}
}