charity campaign

days = int(input())
pastry_cooks = int(input())
cakes_per_day = int(input())
waffles_per_day = int(input())
pancakes_per_day = int(input())

total_cakes_number =  days * pastry_cooks * cakes_per_day
total_waffles_number = days * pastry_cooks * waffles_per_day
total_pancakes_number = days * pastry_cooks * pancakes_per_day

total_cakes_price = total_cakes_number * 45
total_waffles_price = total_waffles_number * 5.80
total_pancakes_price = total_pancakes_number * 3.20

amount_collected = (total_cakes_price + total_pancakes_price + total_waffles_price) * 7 / 8
print(f'{amount_collected:.2f}')