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

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

Node *head = NULL, *tail, *iter;

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=head;itr!=NULL;itr=itr->next)
    printf("%d ",itr->data);
    
}

int main()
{
    int n,num,size,itr;
    scanf("%d",&n);
    if(n<=0)
    {
        
        printf("Invalid input");
        return 0;
    }
    for(itr=0;itr<n;itr++)
    {
        if(!scanf("%d\n",&num))
        {
            printf("Invalid input");
            return 0;
        }
        create(num);
    }
    return 0;
}