Nicola likes to categorize all sorts of things. He categorized a series of numbers and as the result of his efforts, a simple sequence of numbers became a deeply-nested list. Sophia and Stephan don't really understand his organization and need to figure out what it all means. They need your help to understand Nikolas crazy list.
There is a list iterator which contains integers or
other nested lists iterators which...
After that you have to create an iterator object which is linked to this list.