--- Day 4: High-Entropy Passphrases ---
A new system policy has been put in place that requires all accounts to use a passphrase instead of simply a password. A passphrase consists of a series of words (lowercase letters) separated by spaces.
To ensure security, a valid passphrase must contain no duplicate words.
aa bb cc dd eeis valid.
aa bb cc dd aais not valid - the word
aaappears more than once.
aa bb cc dd aaais valid -
aaacount as different words.
The system's full passphrase list is available as your puzzle input. How many passphrases are valid?