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();
	if(N>1 && N<(Math.pow(10, 16)) && M >1 && (Math.pow(10, 4)) > M){
		long O = (N / (M * 1000)) * 1000;
		System.out.println(O);
	}else{
		
	}
}
}