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