#include <algorithm>
#include <iostream>
#include <fstream>
#include <cstdio>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <cmath>
#include <functional>
#include <cassert>
#include <iomanip>
#include <array>
#include <time.h>
#include <limits.h>
#include <numeric>
#define debug(x) cout<<#x<<": "<<x<<endl
#define rep(i,n) for (int i=0;i<(n);i++)
#define FOR(i,a,b) for (int i=(a);i<=(b);i++)
using namespace std;


void solve(){
#ifdef _WIN32
    istream &cin = ifstream("input.txt");
#endif
    long long x = 0, y = 0;
    string str = "";
    cin >> x >> y;
    
	cout << x / (y * 1000) * 1000 << endl;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    solve();
    return 0;
}