#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));
        Node*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++){
        printf("%d",itr->data);
    }
}
int main(){
    int i,num,size;
    scanf("%d",&size);
    if(size<=0){
        printf("Invalid input");
        return 0;
    }
    for(i=0;i<size;i++){
        if(!(scanf("%d",&num)));
        create(num);
    }
    display();
    return 0;
}