counting points only if answered right the first time

Hello!

I need to develop a game like project with quiz questions inserted. The learners should be able to try to answer a question multiple times, but the points should be added to the final score only if they answered correctly the first time.

I am trying to figure out an elegant solution, but so far I got a solution where I add a result slide for each question and I add up the points if a certain visit variable is equal with 1. But I have five parts with 15 questions each. I don't know how to access the values of a quiz slide without inserting the result slide for each question.

Do you have an idea for a better solution?

Thank you!

Anca