def winput():
    inp = input().split()
    if len(inp) == 1:
        return int(inp[0])
    return inp

ist = [True]*10
n = winput()
for i in range(n):
    a, b, c, d, r = winput()
    a, b, c, d = list(map(int, [a, b, c, d]))
    if r == "NO":
        for i in [a, b, c, d]:
            ist[i] = False
    else:
        for i in range(10):
            if not (i in [a, b, c, d]):
                ist[i] = False

for i, b in enumerate(ist):
    if b:
        print(i)
        break