How take input in this problem

#1

i dont understand how take input in this problem

#2

@sksumitkumardiwaker,
Create 2 objects of the linked list class and pass them into the intersection method.
You can create:
LinkedList list1 = new LinkedList();
and
LinkedList list2 = new LinkedList();
Write an add last method in Linked List and pass the input into that:

 public void addLast(int data){
 Node newNode=new Node(data);

 this.size++;
if(head==null){
	head=newNode;
	tail=newNode;
	return;
}
 tail.next=newNode;
 this.tail=newNode;

}