n = gets.chomp.to_i
as = (0..9).to_a
n.times do
  a, b, c, d, r = gets.chomp.split.map { |x| x.length == 1 ? x.to_i : x }
  if r == 'YES'
    as &= [a, b, c, d]
  else
    as -= [a, b, c, d]
  end
end

puts as[0]