#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
    int data;
    struct node *next;
    struct node *prev;
}Node;
Node *head=NULL; *tail, *itr;
void create(int num)
{
    Node *newNode = (Node*)malloc(1*sizeof(Node));
    newNode->data=num;
    newNode->next=NULL;
    if(head==NULL)
    {
        head=newNode;
        tail=newNode;
    }
    else
    {
        newNode->prev=tail;
        tail->next=newNode;
        tail=newNode;
    }
}
void display()
{
    for(itr=head;itr!=NULL;itr=itr->next)
    {
        printf("%d ",itr->data);
    }
}
int main()
{
    int
}