#include <iostream>
#include <string>
using namespace std;
int main(){
    int type;
    cin>>type;
    cin>>ignore(1000,'\n');
    string driver, passenger,route;
    double distance ;
    getline(cin,driver);
    getline(cin,passenger);
    getline(cin,route);
    cin>>distance;
    if(type==1)
        cout<<distance*1.5;
    else if (type==2)
        cout<<distance*0.8;
    else
        cout<<"Invalid input";
        return 0;
}