#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <iomanip>
#include <cmath>
#include <functional>
using namespace std;
#define diff(x,y) ((x > y) ? (x - y) : (y - x))
#define us(x) (x > 0) ? x : x * -1
#define lli long long int
const int MAX = 10000001;

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