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) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] calories = new int[n];
        int temp,no=0,k=0;
        for(int calories_i=0; calories_i < n; calories_i++){
            calories[calories_i] = in.nextInt();
        }
        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                if(a[i]>a[j]){
                    temp=a[i];
                    a[i]=a[j];
                    a[j]=temp;
                }
            }
        }
        for(int i=0;i<n;i++){
            no=no+a[i]*pow(2,k);
        }
        System.out.println(no);// your code goes here
    }
}