package main

import (
	"fmt"
)

func resolve(N int, A, B, C, D []int, R []string) int {
	hint := make([]int, 10)
	for i := 0; i < N; i++ {
		if R[i] == "NO" {
			hint[A[i]] = 1
			hint[B[i]] = 1
			hint[C[i]] = 1
			hint[D[i]] = 1
			continue
		}
		for j := 0; j < 10; j++ {
			switch {
			case j == A[i] && hint[A[i]] != 1:
				hint[A[i]] = 2
			case j == B[i] && hint[B[i]] != 1:
				hint[B[i]] = 2
			case j == C[i] && hint[C[i]] != 1:
				hint[C[i]] = 2
			case j == D[i] && hint[D[i]] != 1:
				hint[D[i]] = 2
			default:
				hint[j] = 1
			}
		}
	}
	for i := 0; i < 10; i++ {
		if hint[i] == 2 {
			return i
		}
	}
	for i := 0; i < 10; i++ {
		if hint[i] == 0 {
			return i
		}
	}
	return 0
}

func main() {
	var N int
	fmt.Scanf("%d\n", &N)
	A := make([]int, N)
	B := make([]int, N)
	C := make([]int, N)
	D := make([]int, N)
	R := make([]string, N)
	for i := 0; i < N; i++ {
		fmt.Scanf("%d %d %d %d %s\n", &A[i], &B[i], &C[i], &D[i], &R[i])
	}
	fmt.Println(resolve(N, A, B, C, D, R))
}