#include<stdio.h>
#include<stdlib.h>
typedef struct node {
    int data;
    struct node *next,*prev;
}Node;
Node *head=NULL,*tail;
Node *create(int num) {
    Node *newnode=(Node*)malloc(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 *itr;
    for(itr=head;itr!=NULL;itr=itr++) {
        printf("%d",itr->data);
    }
}


int main() {
    int size,num,itr,val;
    scanf("%d",&size);
    if(size<0) {
        printf("Invalid iput");
        return 0;
    }
    for(itr=1;itr<=size;itr++) {
        scanf("%d",&num);
        create(num);
     }
    }
     display();
    return 0;
}