AlcoholMarket

import java.util.Scanner;

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

        double priceWhiskey = Double.parseDouble(scanner.nextLine());
        double beerN = Double.parseDouble(scanner.nextLine());
        double wineN = Double.parseDouble(scanner.nextLine());
        double rakiaN = Double.parseDouble(scanner.nextLine());
        double whiskeyN = Double.parseDouble(scanner.nextLine());
        double priceBeer, priceRakia, priceWine, result;

        priceRakia = priceWhiskey/2;
        priceBeer = priceRakia - 0.8*priceRakia;
        priceWine = priceRakia - 0.4*priceRakia;

        result = priceWhiskey*whiskeyN + priceBeer*beerN + priceWine*wineN + priceRakia*rakiaN;

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