def FIND(guesses):
    possible_numbers = set(range(10))
    for guess in guesses:
        numbers, answer = guess
        if answer == 'YES':
            possible_numbers &= set(numbers)
        else:
            possible_numbers -= set(numbers)
    return list(possible_numbers)[0]
Property = []
N = int(input())
for _ in range(N):
  INPUT = input().split()
  A, B, C, D, R = int(INPUT[0]), int(INPUT[1]), int(INPUT[2]), int(INPUT[3]), INPUT[4]
  Property.append(([A, B, C, D], R))
print(FIND(Property))