#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int main(){
    int n,mile=0,i,a,j; 
    int big=0;
    scanf("%d",&n);
    int *calories = malloc(sizeof(int) * n);
    for(int calories_i = 0; calories_i < n; calories_i++){
       scanf("%d",&calories[calories_i]);
    }
    
          for (i = 0; i < n; ++i)
    {
        for (j = i + 1; j < n; ++j)
        {
            if (calories[i] > calories[j])
            {
                a =  calories[i];
                calories[i] = calories[j];
                calories[j] = a;
            }
        }
    }
    int p=0;
    for(int k=n-1;k>=0;k--)
        {
        mile=mile+(calories[k]*2^p);
        p++;
    }
    printf("%d",mile);
    // your code goes here
    return 0;
}