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

typeof 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=newmode;
    }
    else{
        tail->next=newnode;
        newnode->prev=tail;
        tail=newnode;
    }
}

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