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

int main() {

    double price;
    cin >> price;

    double cost = 0.0;

    // write your code here.......
    if (price < 100) {

    } else if (price < 500) {
        cost = price * 0.9;
    } else if (price < 2000) {
        cost = price * 0.8;
    } else if (price < 5000) {
        cost = price * 0.7;
    } else {
        cost = price * 0.6;
    }

    cout << setiosflags(ios::fixed) << setprecision(1) << cost << endl;

    return 0;
}