using System;

public class Program

{

    public static void Main()

    {

        var stari=int.Parse(Console.ReadLine());

        var mladi=int.Parse(Console.ReadLine());

        var night=int.Parse(Console.ReadLine());

        var prevoz=Console.ReadLine();

        double cena_stari=0; double cena_mladi=0;

        switch (prevoz)

            {

            case "train": { if(stari+mladi<50) {cena_stari=24.99; cena_mladi=14.99;}

                           else{cena_stari=24.99*0.5; cena_mladi=14.99*0.5;}}break;

            case "bus": { cena_stari=32.50; cena_mladi=28.50;}break;

            case "boat": { cena_stari=42.99; cena_mladi=39.99;}break;

            case "airplane": { cena_stari=70; cena_mladi=50;}break;

            }

        double transport=stari*cena_stari+mladi*cena_mladi;

        //if(stari+mladi>=50){transport=transport*0.5;}

        /*double transport=stari*cena_stari+mladi*cena_mladi;Console.WriteLine(transport);

        double hotel=night*82.99;Console.WriteLine(hotel);

        double komis=0.1*(transport+hotel);Console.WriteLine(komis);*/

        double razhod=(2*transport+night*82.99)*1.1;

        Console.WriteLine("{0:f2}",razhod);

    }

}