#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    
    long long N,M;
    cin >> N >> M;
    
    N /= 1000;
    
    cout << ( N / M ) * 1000 << endl;
    
    
    return 0;
}