#include <iostream>
#include <iomanip>
using namespace std;
int main() {
double price;
cin >> price;
double cost = 0.0;
// write your code here.......
if (price >= 5000) {
cost = price * 0.6;
} else if (price >= 2000) {
cost = price * 0.7;
} else if (price >= 500) {
cost = price * 0.8;
} else if (price >= 100) {
cost = price * 0.9;
} else {
cost = price;
}
cout << setiosflags(ios::fixed) << setprecision(1) << cost << endl;
return 0;
}