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

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

Node *head,tail;
void create(int num){
    Node *newnode =(Node*) malloc(1 *sizeof(Node));
    newnode->data=num;
    newnode->next=NULL;
    newnode->prev=NULL;
    if(head==NULL){
        head=newnode;
        tail=newnode;
        
    }else{
        newnode->prev=tail;
        tail -> next = newnode;
        tail = newnode;
        
        
    }
}
void display(){
    Node *itr;
    for(itr=0;
    
}