Regex Function about «» and “”

I haven't studied yet how Regex Functions work, so I don't know if my idea can be translated into a function.
I'd like to find paragraphs in which the number of « and » don't match. This can be useful to find some OCR typical errors regarding dialogues (« not closed or viceversa, « or » wrongly recognized...)
The same for “ and ”.
Is this possibile?
Can someone write something like this?

:thanks: