nums = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
n = int(input())

nums_i = []
yn = []
y_num = []

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]:
            if j in nums:
                nums.remove(j)
    else:
        y_num.append(nums_i[i])


if len(nums) == 1:
    print(nums[0])
else:
    ss = set(y_num[0])
    for i in range(1, len(y_num)):
        si = set(y_num[i])
        sa = ss & si
    if len(sa) == 1:
        print(list(sa)[0])
    else:
        for sb in sa:
            if sb in nums:
                print(sb)
                break