#include<stdio.h>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>
#include <stdio.h>

using namespace std;

int main() {

	long long N, M;
	cin >> N >> M;
	cout <<( N / (M*1000) )* 1000<< endl;

	return 0;
}