using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    static void Main(String[] args) {
        int n = Convert.ToInt32(Console.ReadLine());
        string[] calories_temp = Console.ReadLine().Split(' ');
        int[] calories = Array.ConvertAll(calories_temp,Int32.Parse);
        Array.Sort<int>( calories );
        Array.Reverse( calories );
        var sum=0.0;
        for(int i=0;i<n;i++){
            sum += calories[i] * Math.Pow(2,i);
        }
        Console.WriteLine(sum);
    }
}