#include<iostream>
#include<iomanip>
using namespace std;
int main(){
double a;
double b;
cin>>a;
if (a>=0 && a<=150)
{
b=0.4463*a;
}
else if(150<a<=400)
{
b=0.4463*150+0.4663*(a-150);
}
else
{
b=66.945+116.575+(a-400)*0.5663;
}
printf("%.1lf",b);
return 0;
}