package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var rdr = bufio.NewReaderSize(os.Stdin, 1000000)

func main() {
	sc.Split(bufio.ScanWords)
	n := nextInt()
	nums := make([]bool, 10)
	for i := range nums {
		nums[i] = true
	}

	for i := 0; i < n; i++ {
		rNums := make([]int, 0, 4)
		for j := 0; j < 4; j++ {
			rNums = append(rNums, nextInt())
		}
		r := nextLine()
		var ans bool
		if r == "YES" {
			ans = true
		}
		for _, v := range rNums {
			if nums[v] == true {
				nums[v] = ans
			}
		}
	}
	for i, v := range nums {
		if v {
			fmt.Println(i)
			return
		}
	}
}

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	i, _ := strconv.Atoi(nextLine())
	return i
}

func nextInt64() int64 {
	i, _ := strconv.ParseInt(nextLine(), 10, 64)
	return i
}

func nextUint64() uint64 {
	i, _ := strconv.ParseUint(nextLine(), 10, 64)
	return i
}

func nextFloat() float64 {
	f, _ := strconv.ParseFloat(nextLine(), 64)
	return f
}

func readLine() string {
	buf := make([]byte, 0, 1000000)
	for {
		l, p, e := rdr.ReadLine()
		if e != nil {
			panic(e)
		}
		buf = append(buf, l...)
		if !p {
			break
		}
	}
	return string(buf)
}