from collections import defaultdict

N = int(input())
numbers = map(int, input().split())

bits = defaultdict(lambda: 0)

largest_bit = 60

for number in numbers:
    bit = 0
    while number:
        bits[bit] += number & 1
        number >>= 1
        bit += 1

representation = 0

for bit in range(largest_bit + 1):
    if bits[bit] >= 1:
        representation += 2**bit

    bits[bit + 1] += bits[bit] // 2

print(representation)