ans = (1 << 10) - 1

for x in range(int(input())):
    
    tmp = 0
    l = [i for i in input().split(" ")]
    for i in l:
        if '0' <= i and i <= '9':
            tmp += 1 << int(i)
        elif i == "YES":
            ans = ans & tmp
        else:
            ans = ans & ~tmp

cnt = 0
while ans > 0:
    if ans & 1 == 1:
        print(cnt)
    ans = ans >> 1
    cnt += 1