Use the website https://regex101.com/. Note that you can only use (), | (for the books +), and the Kleene Star *. Also assume the alphabet {a b}

You must start the regular expression with a ^ and end with a $ to generate the behavior we desire, and wrap it in (). So in other words ^(stuff goes here)$

Using the following tests.

Just submit a plain text copy of the regular expression as the answer format.

Common sense applies (e.g. do not simply write a regular expression that ORs together all the tests).

MAKE SURE to USE FLAVOR PCRE2 (PHP >= 7.3) for REGEX 101.

Using a regular expression that accepts all words EXCEPT baa, ab, and abb.

These strings should have FULL matching

a

b

aa

bb

ba

aaa

bbb

bba

aab

aba

bab

abba

baba

abab

abbba

babababaabab

These strings should NOT have FULL matching:

baa

ab

abb