#include <iostream>
using namespace std;
class Ride {
    protected:
    string driverName;
    string passengerName;
    string route;
    double distance;
    public:
    Ride(string dName, string pName, string r, double dist) {
        driverName=dName;
        passengerName=pName;
        route=r;
        distance=dist;
    }
    virtual double calculateFare()=0;
};
class CarRide:public Ride {
    public:
    CarRide(string dName, string pName, string r, double dist)
        :Ride(dName, pName, r, dist) {}
        double calculationFare(){
            return distance*1.5;
        }
};
class BikeRide:public Ride {
    public:
    BikeRide(string dName, string pName, string r, double dist)
        :Ride(dName, pName, r, dist) {}
    double claculationFare() {
        return distance*0.8;
    }
};
int main() {
    int rideType;
    cin>>rideType;
    cin.ignore();
    if(rideType!=1&&rideType!=2) {
        cout<<"Invalid input";
        return 0;
    }
    string driverName, passengerName, route;
    double distance;
    getline(cin,driverName);
    getline(cin,passengerName);
    getline(cin,route);
    cin>>distance;
    Ride*ride;
    if(rideType==1) {
        ride=new CarRide(driverName, passengerName, route, distance);
    } else {
        ride=new BikeRide(driverName, passengerName, route, distance);
    }
    cout<<fixed<<setprecision(1)<<ride->calculateFare();
    delete ride;
    return 0;
}