N = int(input())
ns = [list(input().split()) for _ in range(N)]

states = set(range(10))
yesset, noset = set(), set()
for nl in ns:
    r, indexes = nl[-1], set(map(int, nl[:-1]))
    if r == 'YES':
        if yesset:
            yesset &= indexes
        else:
            yesset = indexes
    else:
        noset |= indexes

if answer_set := (yesset - noset):
    answer = answer_set.pop()
else:
    answer = (states - noset).pop()
print(answer)