unconfirmed_users = ['alice', 'brian', 'candace']
confirmed_users = []

while unconfirmed_users:
    current_user = unconfirmed_users.pop()

    print('Verifying user: ' + current_user.title())
    confirmed_users.append(current_user)

print("The following users have been confirmed:")
for confirmed_user in confirmed_users:
    print(confirmed_user.title())

pets = ['cat', 'dog', 'fish', 'cat', 'turtle', 'cat', 'rabbit']

while 'cat' in pets:
    pets.remove('cat')

print(pets)
