#include <iostream>
using namespace std;
struct Node{
int data;
struct Node *next;
struct Node *prev;
};
struct Node* head = NULL;
void insert(int new_data) {
    struct Node* new_node = (struct Node*) malloc(sizeof(struct Node));
    new_node->data=new_data;
    new_node->next = head;
    new_node->prev = NULL;
    if(head != NULL)
    head->prev=new_node;
    head = new_node;
}
void display(){
    struct Node* ptr;
    ptr = head;
    while(ptr != NULL){
        cout<<ptr->data <<" ";
        ptr = ptr->next;
    }
}
int main(){
insert(3);
insert(1);
insert(7);
insert(0);
insert(9);
cout<<"The doubly linked list is";
display();
return 0;
}