#include<iostream>
#include<vector>
#define ll long long
#define P pair<int,int>
#define pb push_back
using namespace std;
int main() {
	ll n,m,ans;
	cin >> n>>m;
	ans = n / m;
	if (ans < 1000) cout <<0<< endl;
	else cout << ans/1000*1000 << endl;
	return 0;
}