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

ans = 0

30.times do |i|
  base = 2 ** i
  last = 0

  A.each.with_index(1) do |a, idx|
    if a[i] == 1
      last = idx
    end

    ans += base * last
  end
end

puts ans