A system supports StrangeID strings, if the string has a "Binary Address Authenticator Bytes", commonly called the "BAAB". A BAAB is any four-character sequence, which consists of a pair of two different characters followed by the reverse of that pair, such as "pqqp", "xzzx", "xoox","adda", etc. However, a supported StrangeID also must NOT have a BAAB within any [square bracket] sequences. There can be many [square bracket] sequences in one StrangeID.
Write a PHP program to find out how many StrangeIDs in your puzzle input (given below) are supported by the system? Your PHP program should only output an integer value of the number of StrangeIDs that are supported.
The output of your program, that is the total number (integer) of supported StrangeIDs.