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

int main() {
    
    double price;
    cin >> price;

    double cost = 0.0;

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

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

    return 0;
}