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

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

    double cost = 0.0;

    // write your code here.......
    if(price>=100 && price<500)
    {
        price*=0.9;
    }
    else if(price>=500 && price<2000)
    {
        price*= 0.8;
    }
    else if(price>=2000 && price<5000)
    {
        price*=0.7;
    }
    else 
    {
        price*=0.6;
    }
    cost = price;
    cout << setiosflags(ios::fixed) << setprecision(1) << cost << endl;

    return 0;
}