#include <iostream>
using namespace std;
int main() {
    int a;
    cin >> a;
    if(a >= 100 and a < 500){
        printf("%.1f", a * 1.0 * 0.9);
    }
    else if(a >= 500 and a < 2000){
        printf("%.1f", a * 1.0 * 0.8);
    }
    else if(a >= 2000 and a < 5000){
        printf("%.1f", a * 1.0 * 0.7);
    }
    else{
        printf("%.1f", a * 1.0 * 0.6);
    }
    return 0;
}