N = int(input())
can = [0] * 10
for i in range(N):
    a, b, c, d, r = input().split()
    g = list(map(int, [a, b, c, d]))
    if r == "NO":
        for x in g:
            can[x] = 1
    else:
        for j in range(10):
            if j not in g:
                can[j] = 1
print(can.index(0))