#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
    int data;
    struct node *next;
    struct node *prev;
}Node;
Node *head=NULL, *tail;
void create(int num)
{
    Node *newNode=(Node*) malloc (1 * sizeof(Node));
    newNode->data=num;
    newNode->next=NULL;
    new
    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);
 }printf("\n");
 for(itr=head;itr!=tail;itr=itr->next)
 {
     printf("%d ",itr->data);
 }
}
int main()
{
    int n,i,num;
    scanf("%d",&n);
    if(n<0)
    {
        printf("Invalid input");
        return 0;
    }
    for(i=1;i<=n;i++)
    {
        scanf("%d",&num);
        create(num);
    }
    display();
    return 0;
}