#include<iostream>
#include<iomanip>
using namespace std;
void calcost(string membershipType,int discountStatus,float duration)
{
    float monthlyCost= 0.0;
    if(membershipType == "Basic")
    {
        monthlyCost =30.0;
    }
    else if(membershipType == "Standard")
    {
        monthlyCost =50.0;
    }
    else if(membershipType == "premium")
    {
        monthlyCost =80.0;
    }
    float total = monthlyCost * duration ;
    if (discountStatus == 1 )
    {
        total *=0.8;
    }
    return total;
}
int main()
{
    string membershipType;
    int discountStatus;
    float duration;
    cin>>discountStatus;
    float result = calcost(mambershipType, discountStatus , duration);
    if(result<0)
    {
        cout<<"Invalid input"<<endl;
    }
    else
    {
        cout<<fixed<<setprecision(2)<<result<<endl;
        
    }
    return 0;
}