suppose a computer's login mechanism first asks for a user name, and then for the password, regardless of whether or not the login name is that of a valid user. Herman the Hacker has a list of $10,000$ commonly used login names, and a list of $100,000$ commonly used passwords. On this computer, there are $100$ accounts that have both a login name on the first list and a password on the second list. For simplicity, assume that no other accounts have either a login name or password on these lists.