n = int(input())
OK = set(range(10))
NG = set()
for _ in range(n):
    L = list(input().split())
    r = L[4]
    L = list(map(int, L[:4]))
    if r == "YES":
        OK &= set(L)
    else:
        NG |= set(L)

for i in range(10):
    if i in NG:
        continue
    if i in OK:
        print(i)
        break