import java.util.Scanner;

public class CharitiCampaign {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int days = Integer.parseInt(scanner.nextLine());
        int cooks = Integer.parseInt(scanner.nextLine());
        int cakes = Integer.parseInt(scanner.nextLine());
        int waffles = Integer.parseInt(scanner.nextLine());
        int pancakes = Integer.parseInt(scanner.nextLine());

        double incomeCakes = days*cooks*cakes*45;
        double incomeWaffles = days*cooks*waffles*5.80;
        double incomePancakes = days*cooks*pancakes*3.20;
        double totalIncome = incomeCakes+incomePancakes+incomeWaffles;
        double result = totalIncome*7/8;
        System.out.printf("%.2f", result);
    }
}