N = int(input())
candi = set(list(range(10)))
for _ in range(N):
    a,b,c,d,r = input().split()
    A = [a,b,c,d]
    A = list(map(int,A))
    if r == "NO":
        for a in A:
            if a in candi:
                candi.remove(a)
    else:
        candi &= set(A)

print(candi.pop())