N = int(input())
yes = {i for i in range(10)}
for i in range(N):
    question = input().split()
    nums = map(int,question[:-1])
    ans = question[-1]
    if ans == "NO":
        temp = list(yes)
        for num in nums:
            if num in temp:
                temp.remove(num)
        yes = set(temp)
    else:
        yes&=set(nums)
print(list(yes)[0])