fun main()
{
    val N = readLine()!!.toInt()
    var candidates = (0..9).toSet()
    repeat (N) {
        val line = readLine()!!.split(" ")
        val abcd = line.take(4).map(String::toInt)
        if (line.last() == "YES") {
            candidates = candidates.intersect(abcd)
        } else {
            candidates -= abcd
        }
    }
    println(candidates.first())
}