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

class FastReader {
public:
    FastReader() { ios::sync_with_stdio(false); cin.tie(nullptr); }
    int nextInt() { int x; cin >> x; return x; }
};

class FastWriter {
public:
    void print(long long x) { cout << x; }
};

int main() {
    try {
        FastReader in;
        FastWriter out;
        int testcases = 1;  /* testcases = in.nextInt(); */
        
        while (testcases-- > 0) {
            int tokens = in.nextInt();
            int type1 = tokens / 500;
            tokens %= 500;
            int type2 = tokens / 5;
            long long ans = type1 * 1000LL + type2 * 5LL;
            out.print(ans);
        }
    } catch (exception& e) {
        cerr << e.what() << endl;
        return 1;
    }
    return 0;
}