inpl = lambda: list(map(int,input().split()))
N = int(input())
cand = set(range(10))
for _ in range(N):
    turn = input().split()
    R = turn[-1]
    ABCD = set(map(int,turn[:-1]))
    if R == 'YES':
        cand &= ABCD
    else:
        cand -= ABCD
print(list(cand)[0])