class Calc0104
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @s = args.shift.first || ''
  end

  def run
    c = 1
    @s.split(//).each do |b|
      case b
      when 'L'
        c = c * 2
      when 'R'
        c = c * 2 + 1
      end
    end
    c
  end
end

puts Calc0104.new(STDIN.readlines).run if __FILE__ == $0