#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define MAX 100
typedef struct node{
    char data[MAX];
    struct node *prev;
    struct node *next;

}Node;
    Node *head=NULL, *tail;
    void create(char *ch){
    Node *newnode=(Node*)malloc(sizeof(Node));
    strcpy(newnode->data,ch);
    newnode->prev=NULL;
    newnode->next=NULL;
    if(head==NULL){
        head=newnode;
        tail=newnode;
    }
    else{
        newnode->prev=tail;
        tail->next=newnode;
        tail=newnode;
    }
}
void display(){
    Node *itr=tail;
    for(itr=head;itr=itr->next){
        printf("%s",itr->data);
    }
}
    int main(){
        int n,num;
        scanf("%d",&n);
        if(n<0){
            printf("Invalid input");
            return 0;
        }
        char ch[20];
        for(int i=0;i<n;i++){
            if(scanf("%s",ch)==1){
                create(ch);
            }
        }
        display();
            return 0;
        }