#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>


typedef struct Node {
    int data;
    struct Node* next;
    struct Node* prev;
} Node;


Node* createNode(int data) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    if (!newNode) {
        printf("Memory error\n");
        return NULL;
    }
    newNode->data = data;
    newNode->next = newNode->prev = NULL;
    return newNode;
}


void insertNode(Node** head, int data) {
    Node* newNode = createNode(data);
    if (*head == NULL) {
        *head = newNode;
    } else {
        Node* temp = *head;
        while (temp->next) {
            temp = temp->next;
        }
        temp->next = newNode;
        newNode->prev = temp;
    }
}

// Function to swap data of two nodes
void swap(Node* a, Node* b) {
    int temp = a->