#include <bits/stdc++.h>
using namespace std;

int main() {
	int64_t N, M;
	cin >> N >> M;

	int64_t n = N / M;
	int64_t a = 0;
	if (n < 1000) {
		a = 0;
	}
	else {
		a = n / 1000;
		a *= 1000;
	}

	cout << a << endl;
}