#include <bits/stdc++.h>
using namespace std;

int main() {
    long long N;
    cin >> N;
    long long lanterns = N / 500;
    long long remaining_tokens = N % 500;
    long long banners = remaining_tokens / 5;
    
    long long festivity_points = (lanterns * 1000) + (banners * 5);
    cout << festivity_points << endl;
    
    return 0;
}