// Node class to create a new node in the linked list
class Node {
    constructor(data) {
        this.data = data;
        this.next = null;
    }
}

// Linked List class
class LinkedList {
    constructor() {
        this.head = null;
    }

    // Method to add a new node at the end of the list
    append(data) {
        let newNode = new Node(data);
        if (this.head === null) {
            this.head = newNode;
        } else {
            let current = this.head;
            while (current.next !== null) {
                current = current.next;
            }
            current.next = newNode;
        }
    }

    // Method to check if two linked lists are identical
    areIdentical(listb) {
        return areIdenticalRecur(this.head, listb.head);
    }
}

// Recursive function to check if two linked lists are identical
function areIdenticalRecur(a, b) {
    // If both lists are empty
    if (a == null && b == null) return true;

    // If both lists are not empty, then
    // data of current nodes must match,
    // and same should be recursively true
    // for rest of the nodes.
    if (a != null && b != null)
        return a.data === b.data && areIdenticalRecur(a.next, b.next);

    // If we reach here, then one of the lists
    // is empty and other is not
    return false;
}

// Creating two linked lists
let list1 = new LinkedList();
let list2 = new LinkedList();

// Adding nodes to the first list
list1.append(1);
list1.append(2);
list1.append(3);

// Adding nodes to the second list
list2.append(1);
list2.append(2);
list2.append(3);

// Check if the two linked lists are identical
if (list1.areIdentical(list2)) {
    console.log("The linked lists are identical.");
} else {
    console.log("The linked lists are not identical.");
}

// Modifying the second list to make it different
list2.append(4);

// Check again after modifying the second list
if (list1.areIdentical(list2)) {
    console.log("The linked lists are identical.");
} else {
    console.log("The linked lists are not identical.");
}