Oh, ok.

So that means I need to implement Checking if all elements in the list are INT and if not, to zip out to the main list.

But seems odd that you got this list. Instructions says nothing about this type of list.

Because you are using set with list and I believe task required only one list.
The loop will not work with List inside the set, I think this should look diffrent If we want to check if any element inside our list/set is INT.

You should provide only list of Intigers