Slides counter

Hi

Is there a possibility to count remaining slides when I do not know their exact amount?

I have a quiz with 1 attempt to retake it.

When user clicks Retake, there are displaying only previously incorrectly answered questions.

So if at 1st try there are displaying all 9 slides, on 2nd try the displayed slides number depends on concrete case.

But my issue is that I would like to show the progress - how many slides user should complete on retake.

Like '1 out of 5'

Thanks