# frozen_string_literal: true

# Current positions.
class Array
  def solve_rec(rst) # rubocop:todo Metrics/AbcSize
    if empty? || rst > N
      -1
    else
      # Avoid block chain is slow.
      m = map do |x|
        c = x.digits(2).sum
        [x + c, x - c]
      end.flatten.filter { _1 > 1 && _1 <= N }.uniq
      m.include?(N) ? rst + 1 : m.solve_rec(rst + 1)
    end
  end
end

N = gets.to_i

RESULT = [1].solve_rec(1)

puts RESULT