class Calc0024
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @n = args.shift.first.to_i
    @tries = args.map { |l| [l[0..3].map(&:to_i), l[4] == 'YES'] }
  end

  def run
    a = (0..9).to_a
    @tries.each do |b, r|
      if r
        a = a & b
      else
        a = a - b
      end
    end
    a.first
  end
end

puts Calc0024.new(STDIN.readlines).run if __FILE__ == $0