#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>
#include <queue>
#include <complex>

#define INF 1145141919
#define EPS 1e-9
#define Pi acos(-1)

using namespace std;

typedef long long ll;

ll N, M;

int main(){

	cin >> N;
	cin >> M;

	cout << N / M / 1000 * 1000 << endl;


	return 0;

}