#include<stdio.h>
#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{
tail->next=newnode;
tail=newnode;
newnode->prev=head;
}
}
void display(int num) {
    Node *itr;
    for(itr=head;itr!=NULL;itr=itr->data){
        printf("%d",itr->data);
    }
}

int main() {
    int size,arr[size],itr;
    scanf("%d",&size);
    if(size<=0){
        printf("Invalid input");
        return 0;
    }
    for(itr=2;itr<size;itr++){
        scanf("%d",&size);
    }
    create(num);
}
display();