N = gets.to_i
A = gets.split.map(&:to_i)

def shift(x)
  x / 2 + 2 ** 15 * (x % 2)
end

if N >= 16
  puts 2 ** 16 - 1
  exit
end

L = 2 ** N
dp = Array.new(L, 0)

L.times do |mask|
  N.times do |i|
    next if mask[i] != 0
    nmask = mask | (1 << i)
    a = A[i]

    16.times do |j|
      a = shift(a)
      nv = dp[mask] | a
      dp[nmask] = nv if dp[nmask] < nv
    end
  end
end

pp dp[L - 1]