n = int(input())
lst = [1 for _ in range(10)]
for _ in range(n):
    a, b, c, d, r = input().split()
    if r == "YES":
        for i in range(10):
            if str(i) not in [a, b, c, d]:
                lst[i] = 0
    else:
        for i in [a, b, c, d]:
            lst[int(i)] = 0
print(lst.index(1))