N = int(input())
numbers = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0'}

for i in range(N):
    A, B, C, D, R = input().split()
    if R == 'YES':
        numbers = numbers & {A, B, C, D}
    else:
        numbers = numbers - {A, B, C, D}

result = list(numbers)
print(result[0])