// editor2
#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<<endl;
else if(type ==2)
cout<<distance*0.8;
else
cout<<"Invalid input";
return 0;
}