#include <bits/stdc++.h>
using namespace std;

// Node class representing a single digit in the linked list
class Node {
public:
    int data;
    Node* next;

    Node(int value) {
        data = value;
        next = nullptr;
    }
};

// LinkedList class to manage node-level operations
class LinkedList {
public:
    // function to insert digit at the end
    Node* append(Node* head, int value) {
        Node* newNode = new Node(value);
        if (!head) {
            return newNode;
        }
        Node* current = head;
        while (current->next)
            current = current->next;
        current->next = newNode;
        return head;
    }

    // Function to print the list
    void printList(Node* head) {
        Node* current = head;
        while (current) {
            cout << current->data;
            current = current->next;
        }
        cout << endl;
    }
};

// Solution class having the addOne logic 
class Solution {
public:
    // function to reverse the linked list
    Node* reverseList(Node* node) {
        Node* prev = nullptr;
        Node* current = node;

        while (current) {
            Node* nextNode = current->next;
            current->next = prev;
            prev = current;
            current = nextNode;
        }
        return prev;
    }

    // Function to add one to the number represented by the linked list
    Node* addOne(Node* head) {
        // Reverse the list to make least significant digit accessible
        head = reverseList(head);

        Node* current = he