n = gets.to_i
no = Array.new(10) { 0 }
arr = [*0..9]

n.times do
  *num, op = gets.split
  num.map!(&:to_i)

  if op == 'YES'
    (arr - num).each { |e| no[e] = 1 }
  else
    num.each { |e| no[e] = 1 }
  end
end

puts no.find_index(0)