n, y = [], []
c = 0
for i in range(int(input())):
    l = input().split()
    if l[4] == "NO":
        n += l[:-1]
    else:
        y += l[:-1]
        c += 1
s = "".join([x for x in set(y) if y.count(x) == c]) if c else "0123456789"
for i in s:
    if not i in n : print(i)