#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; 
    scanf("%d",&n);
    int *calories = malloc(sizeof(int) * n);
    for(int calories_i = 0; calories_i < n; calories_i++){
       scanf("%d",&calories[calories_i]);
    }
    // where magic happens
    long int miles = 0;
    
    //sorting the calories array in ascending order
    
    for(int i =0; i < n - 1; i++)
        for(int j = 0; j < n - i - 1; j++)
        {
        if(calories[j] < calories[j+1])
            {
            int temp = calories[j];
            calories[j] = calories[j+1];
            calories[j+1] = temp;
        }
    }
    
    //applying the mathematical formula for the problem
    
    
    for(int i = 0; i < n; i++)
        {
        miles = miles + (calories[i] * pow(2,i));
    }
    printf("%ld",miles);
    
    
    
    
    return 0;
}