#include <iostream>
using namespace std;
int  main(){
    int ridetype;
    string driver,passenger,route;
    double distance;
    
    cin>>ridetype;
    cin.ignore();
    getline(cin,driver);
    getline(cin,passenger);
    getline(cin,route);
    cin>>distance;
    if(ridetype<1||ridetype>2){
        cout<<"Invalid input";
        return 0;
    }
    if (driver.length()<1||
    driver.length()>100||
    passenger.length()<1||
    passenger.;ength()>100||
    route.length()<1||
    route.length()>100){
        cput<<"Invalid input";
        return 0;
        
    }
    double fare;
    if(ridetype==1){
    fare=distance*1.5;}
    else{
        fare=distance*0.8;
    }
    cout<<fare;
    return 0;
}