N = int(input())
n = [0] * N
for i in range(N):
    n[i] = input().split()
ans = set((0, 1, 2, 3, 4, 5, 6, 7, 8, 9))

for i in range(len(n)):
    m = map(int, n[i][:4])
    if n[i][4] == 'NO':
        ans = set(ans) - set(m)
    if n[i][4] == 'YES':
        ans = set(ans) & set(m)

print(list(ans)[0])