#include <iostream>
#include <iomanip>
using namespace std;

int main() {
    double price;

    cin >> price;
    
    if(price >= 5000) price *= 0.6;
    else if(price >= 2000) price *= 0.7;
    else if(price >= 500) price *= 0.8;
    else if(price >= 100) price *= 0.9;

    cout << price;

    return 0;
}