#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;


int main(){
	long long n,m;
	cin >> n >> m;
	cout << ((n/m)/1000) * 1000 << endl;
	return 0;
}