CharityCompaign

import java.util.Scanner;

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

        int days = Integer.parseInt(scanner.nextLine());
        int cooks = Integer.parseInt(scanner.nextLine());

        double cakes = Double.parseDouble(scanner.nextLine());
        double waffles = Double.parseDouble(scanner.nextLine());
        double pancakes = Double.parseDouble(scanner.nextLine());

        double result, total, charity, perCook;

        perCook = cakes*45 + waffles*5.80 + pancakes * 3.20;
        result = days*cooks;
        total = result * perCook;
        charity = total - total/8;

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