#coding: UTF-8

import sys
from math import pi
from collections import deque
from functools import reduce

### defs ###

### main ###
N = int(sys.stdin.readline())
ABCDR = []
ans=[1]*10
for _ in range(N):
	a,b,c,d,r = sys.stdin.readline().strip('\r\n').split()
	a=int(a)
	b=int(b)
	c=int(c)
	d=int(d)
	if(r=='NO'):
		ans[a]=0
		ans[b]=0
		ans[c]=0
		ans[d]=0
	else:
		for i in range(10):
			if(i in (a,b,c,d)):
				continue
			ans[i]=0
print(ans.index(1))