DoublyLinkedListNode *t = new DoublyLinkedListNode(data); 
    
    if(llist==nullptr ){
        return t; 
    }
    
    else if( llist->next==nullptr && llist->data<data){
        llist->next=t;
        t->prev=llist;
    }
    else if(llist->data >data){
        DoublyLinkedListNode *te = new DoublyLinkedListNode(llist->data);
        DoublyLinkedListNode* Next=llist->next;
        llist->data=data;
        te->next=llist->next;
        Next->prev=te;
        te->prev=llist;
        llist->next=te;
        return llist;
    }
    DoublyLinkedListNode* temp =llist;
    while(temp->next!=nullptr){
        temp=temp->next;
    }
    if(temp->data<data){
        temp->next=t;
        return llist;
    }
    temp=llist;
    while(temp->data < data){
        temp = temp->next;
    }
    DoublyLinkedListNode* temp2 =temp->prev;
    cout<<temp2->data;
    temp2->next=t;
    t->prev=temp2;    
    t->next=temp;
    temp->prev=t;
    return llist;