#include <iostream>
using namespace std;
#define ll long long

int main(){
    ll n, m, res = 0;
    cin >> n >> m;
    if(n/m < 1000){
        cout << 0 << endl;
    }else{
        res = (n/m) / 1000 * 1000;
        cout << res << endl;
    }
    
    return 0;
}