Where did the expression A and a come from?

The expression "A and a" is not a common or established idiom in English. It's possible that you're thinking of a different phrase, or the phrase is specific to a certain context or region.

To understand where this might have come from, please provide more context:

* What is the full sentence or phrase where you heard "A and a"?

* What is the general topic or situation where you encountered it?

* Are there any other words or phrases surrounding it?

Knowing more details about the situation can help me understand the origin of the expression.