import java.util.Scanner;

public class CharityEvent {
    public static void main(String[] args) {
            Scanner sladko = new Scanner(System. in);

            int countDays = Integer.parseInt(sladko.nextLine());
            int countChefs = Integer.parseInt(sladko.nextLine());
            int countCakes = Integer.parseInt(sladko.nextLine());
            int countWaffles = Integer.parseInt(sladko.nextLine());
            int countPancakes = Integer.parseInt(sladko.nextLine());
            int priceCake = 45;
            double priceWaffle = 5.80;
            double pricePancake = 3.20;


            double pechalba = countCakes*priceCake + countPancakes*pricePancake + countWaffles*priceWaffle;
            double obshto = pechalba*countChefs*countDays;
            double razhodi = obshto/8;
            double chisto = obshto - razhodi;

        System.out.printf("%.2f",chisto);

    }
}