import java.util.*;

public class NestedList<E, T extends Iterable<E>> implements Iterable<E> {
    private final List<T> list;

    public NestedList(List<T> innerLists) {
        list = List.copyOf(innerLists);
    }

    @SafeVarargs
    public NestedList(T... innerLists){
        list = new ArrayList<>();
        Collections.addAll(list, innerLists);
    }

    @Override
    public Iterator<E> iterator() {
            // Implementujte tuto metodu.
    }
}