#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;
    newNode->prev=NULL;
    if(head==NULL)
    {
     head=newNode;
     tail=newNode;
    }
    else
    {
        newNode->prev=tail;
        tail->next=newNode;
        tail=newNode;
    }
}
void display()
{
    Node*i;
    for(i=head;i!=NULL;i=i->next)
    {
        printf("%d",i->data);
    }
}
int main()
{
    int i,n,num
    scanf("%d",&n);
    if(n<=0)
    {
        printf("Invalid input");
        return 0;
    }
    for(i=1;i<=n;i++)
    {
        if(scanf("%d",&num)!=1)
        {
            printf("Invalid input");
            return 0;
        }
        create(num);
    }
    display();
}