#!/usr/bin/env python

N = int(input())
inlines = []
for i in range(N):
    inlines.append(input().split())

yescount = 0
yesnums = []
nonums = []
for line in inlines:
    if line[4] == 'YES':
        yesnums += line[:4]
        yescount += 1
    else:
        nonums += line[:4]

if len(set(nonums)) == 9:
    ans = list(set(range(10)) - set(map(int, nonums)))
    print(ans[0])
    exit()

for i in set(yesnums):
    if yesnums.count(i)==yescount and nonums.count(i)==0:
        print(i)