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

float calculatemembershipCost(string membershipType,int discountstatus,float duration){
    
    if (duration <=0||duration>10)
    return-1;

unordered_map<string,float>plans={
    {
        "Basic",30.0
    },
    {
        "Standard",50.0
    },
    {
        "Premium",80.0
    }
};
    
    if (plans.find(membershipType)==plans.end())
    return-1;
    if (discountstatus !=0 && discountstatus!=1)
    return-1;
    float cost=plans[membershipType]*duration;
    if (discountstatus==1)
    cost*=0.8;
    return cost;
}  
 
int main(){
    string membershipType;
    int discountStatus;
    float duration;
    
    cin>>membershipType>>discountStatus>>duration;
    
    float total=calculatemembershipCost(membershipType,discountStatus,duration);
    
    if(total==-1)
    cout <<"invalid input"<<endl;
    else
    cout<<fixed<<setprecision(2)<<total<,endl; 
    
    return 0;
}