import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        long miles=0;
        long p=1;
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] calories = new int[n];
        for(int calories_i=0; calories_i < n; calories_i++){
            calories[calories_i] = in.nextInt();
        }
        // your code goes here
        for(int i = 0; i<n ; i++)
            {
                for(int j = i ; j<n-1 ; j++)
                {
                    if (calories[j]>calories[j+1])
                    {
                    int temp;
                    temp = calories[j]; 
                    calories[j] = calories[j+1];
                    calories[j+1] = temp;
                    }
                }
            }
        for(int i = n-1 ; i>=0 ; --i)
          {
            
                  miles = miles+calories[i]*p;
            p = p*2;
        }
        System.out.println(miles);
    }
}