#include<iostream>
#include<iomanip>
using namespace std;
int main(){
    int ridetype;
    string driver,passenger;
    double distance,fare;
    cin>>ridetype;
    cin>>driver>>passenger;
    cin.ignore();
    getline(cin,route);
    cin>>distance;
    if(ridetype==1){
        fare=1.5*distance;
    }
    else if(ridetype==2){
        fare=0.8*distance;
    }
    else{
        cout<<"Invalid input";
        return 0;
    }
    cout<<fare;
    return 0;
}