#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

float calculatemMembershipCost(string
membershipType, int discountstatus, float duration)
{
    if(membershipType == "basic")
       CostperMonth = 30;
    else if (membershipType =="Standard")
       CostperMonth = 50;
    else if (membershipType =="premium")
        CostperMonth = 80;
    else
    return -1;
    
    if (discountaStatus <0 || discountStatus> 1 || duration <=0)
    return -1;
    
    float total= CostperMonth* duration;
    
    if(discountStatus == 1)
    total*=0.8;
    return total;
}
int main(){
    string membershipType;
    int discountStatus;
    float duration;
    
    cin >> membershipType >> discountstatus >>
    duration;
    
    float result =
    calculateMembershipCost(membershipType,
    discountStatus, duration)
    
    if (result ==-1)
    cout<< "invalid input"<< endl;
    }else{
    cout << fixed << setprecision(2) << result
    << endl;
    return 0;
}