#include <iostream>

using namespace std;
//変数デバッグ
#define DEB(variable) cout << #variable << "=" << variable << endl

//for簡易表記(引数ミス防止)
#define INFOR(inc, a, b) for (int inc = (a); (inc) < (b); (inc)++) //incをaにし、b-a回(iがb未満の間)処理を行う
#define DEFOR(inc, a, b) for ((inc) = (a); (inc) > (b); (inc)--)   //incをaにし、a-b回(iがbより大きい間)処理を行う

int main(){

    long long int m,n;
    cin >> m >> n;
    m /= 1000;

    cout << (m / n) * 1000 << endl;

    return 0;
}