def login_client(client, username):
    client.connect()
    phone = '+79663742000' + str(random.randint(0, 9999)).zfill(4)
    client.send_code_request(phone)
    while True:
        try:
            print('Signing up as', phone)
            client.sign_up('22222', username, 'User')
            break
        except PhoneNumberOccupiedError:
            try:
                print('Signing in as', phone)
                client.sign_in(phone, '22222')
                break
            except SessionPasswordNeededError:
                print('Occupied', phone, 'had password! Deleting!')
                client(functions.account.DeleteAccountRequest(''))

    print('Changing', phone, 'username to', username)
    client(functions.account.UpdateUsernameRequest(username))