import java.util.Scanner;

public class AlcoholMarket {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        double whiskeyPrice = Double.parseDouble(scan.nextLine());
        double beer = Double.parseDouble(scan.nextLine());
        double whine = Double.parseDouble(scan.nextLine());
        double rakiq = Double.parseDouble(scan.nextLine());
        double whiskey = Double.parseDouble(scan.nextLine());
        double rakiqPrice = whiskeyPrice - (whiskeyPrice * 0.5);
        double whinePrice = rakiqPrice - (rakiqPrice * 0.4);
        double beerPrice = rakiqPrice - (rakiqPrice * 0.8);
        double rakiqSum = rakiq * rakiqPrice;
        double beerSum = beer * beerPrice;
        double whineSum = whine * whinePrice;
        double whiskeySum = whiskey * whiskeyPrice;
        double finalPrice = rakiqSum + beerSum + whineSum + whiskeySum;
        System.out.printf("%.2f", finalPrice);



    }
}