Users of computers frequently enter URLs (Uniform Resource Locators) in the
For example, in the URL
the protocol is "http", the server is "www", and the network is "monkey.donkey.zebra.com".
For purposes of this problem, the protocol and server are alphanumeric strings,
whereas the network is an alphanumeric string that may also contain periods
(however, the URL cannot end with a period or contain two consecutive periods).