nums_x = [-1, -1, -1, -1, -1, -1, -1, -1, -1, -1]
n = int(input())

nums_i = []
yn = []

for _ in range(n):
    t = input().split()
    yn.append(t.pop(-1))
    nums_i.append(list(map(int, t)))

for i in range(n):
    if yn[i] == "NO":
        for j in nums_i[i]:
            nums_x[j] = 0
    else:
        nums = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
        for j in nums_i[i]:
            nums.remove(j)

        for n in nums:
            nums_x[n] = 0

for i in range(len(nums_x)):
    if nums_x[i] == -1:
        print(i)
        break