package com.company;

import java.util.Scanner;

public class Main {


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

            int project = Integer.parseInt(scanner.nextLine());
            double money_price = Double.parseDouble(scanner.nextLine());

            double sum = 0;
            double total_sum=0;

            for (int i = 0; i <project; i++) {
                int points= Integer.parseInt(scanner.nextLine());
                if (i%2==1) {
                    sum += points * 2;
                } else {
                    sum+=points;

                }

            }
            total_sum=money_price*sum;
            System.out.printf("The project prize was %.2f lv.", total_sum);
        }
    }