#!/bin/python

import sys


n = int(raw_input().strip())
calories = map(int, raw_input().strip().split(' '))
# your code goes here
calories.sort()
calories.reverse()
miles = 0
for i in range (0, len(calories)):
    miles = miles + (calories[i]* pow(2, i))
    #print miles, calories[i]
print miles