import java.util.Scanner;

class Main {
  public static void main(String[] args) {
  Scanner scanner = new Scanner(System.in);
  double days = Double.parseDouble (scanner.nextLine());
  int pastryCook = Integer.parseInt(scanner.nextLine());
  double cakesQuantity = Double.parseDouble (scanner.nextLine());
  double wafflesQuantity = Double.parseDouble (scanner.nextLine());
  double pancakesQuantity = Double.parseDouble (scanner.nextLine());

  double cakesSum = (cakesQuantity * 45);
  double wafflesSum = (wafflesQuantity * 5.80);
  double pancakesSum = (pancakesQuantity * 3.20);

  double totalSum_1day = (cakesSum + wafflesSum + pancakesSum)*8;
  double totalCampaign = (totalSum_1day * days);
  double rest = totalCampaign - (1/8 * totalCampaign);

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


  }
}