import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

n = int(readline())
check = set([str(i + 1) for i in range(9)])
for i in range(n):
    abcdr = readline().rstrip().decode()
    abcd = {abcdr[0], abcdr[2], abcdr[4], abcdr[6]}
    if abcdr[8:] == 'YES':
        check = check & abcd
    else:
        check = check - abcd
print(check)