N = int(input())
f = [True]*10
for _ in range(N):
    A, B, C, D, R = input().split()
    x = set(map(int, [A, B, C, D]))
    if R == "YES":
        for i in range(10):
            if i not in x:
                f[i] = False
    if R == "NO":
        for i in range(10):
            if i in x:
                f[i] = False
print(f.index(True))