#!/bin/python3
import sys
n = int(input().strip())
calories = list(map(int, input().strip().split(' ')))
calories.sort()
s=calories[::-1]
max=0
j=0
p=0
for i in (s):
    p=p+i*(2**(j))
    j+=1
    if p>max:
        max=p
print(max)        
# your code goes here