#include <iostream>
using namespace std;
int main(){
int x;
cin >> x;
if(x <= 15){
a = x0.47;
printf("%.2f",a);
}else if(x > 15 and x <= 30){
a = x-15;
b = a0.89+150.47;
printf("%.2f",b);
}else{
a = x-15;
b = x-30;
c = a0.89+b+15*0.47;
printf("%.2f",c);
return 0;
}