# coding: utf-8

n = int(input())
list_ = [0,1,2,3,4,5,6,7,8,9]
for i in range(n):
    l = input().split(" ")
    s = list(map(int,l[:4]))
    yn = l[4]
    if yn == "NO":
        for j in s:
            if j in list_:
                list_.remove(j)
    else:
        rem_l = [0,1,2,3,4,5,6,7,8,9]
        for j in s:
            rem_l.remove(j)
        for j in rem_l:
            if j in list_:
                list_.remove(j)
print(list_[0])