#!/usr/bin/env python3
#fileencoding: utf-8

N = int(input())
qa = [[int(v) if i < 4 else v for i,v in enumerate(input().strip().split(" "))] for i in range(N)]

ans = set([i for i in range(10)])
no = set([])
yes = set([i for i in range(10)])
for i in range(N):
    if qa[i][4] == "NO":
        no = no | set(qa[i][:4])
    else:
        yes = yes & set(qa[i][:4])

if len(no) == 9:
    print(list(ans-no)[0])
elif len(yes) == 1:
    print(list(yes)[0])
else:
    print(list(yes-no)[0])