# coding: utf-8

result = set([i for i in range(10)])
N = int(input())

for i in range(N):
    abcdr = input().split()
    A, B, C, D = [int(abcdr[j]) for j in range(4)]
    R = abcdr[4]

    if R == "NO":
        result = result - set([A, B, C, D])
    else:
        result = result & set([A, B, C, D])

print(list(result)[0])