def print_func(not_arrived_quests):
    print(len(not_arrived_quests))
    for person in sorted(not_arrived_quests):
        print(person)


n = int(input())

invited_guests = set()
arrived_quests = set()

for _ in range(n):
    guest = input()

    invited_guests.add(guest)

while True:
    data = input()

    if data == "END":
        break
    arrived_quests.add(data)

missed_quests = invited_guests.difference(arrived_quests)

print_func(missed_quests)