N = int(input())

numbers = set(range(10))

for _ in range(N):
    ABCD_R = input().split()

    R = ABCD_R.pop()
    ABCD = [int(i) for i in ABCD_R]

    if R == 'YES':
        numbers &= set(ABCD)
    elif R == 'NO':
        numbers -= set(ABCD)

if len(numbers) == 1:
    print(list(numbers)[0])