def mask_phone(phone):
    if not phone:
        return phone
    return '{}****{}'.format(phone[:3], phone[-4:])


def mask_email(email):
    if not email:
        return email
    email_account, email_domain = email.split('@')
    if len(email_account) > 2:
        email_account = email_account[:2] + '***'
    else:
        email_account = '***'
    return '{}@{}'.format(email_account, email_domain)