// editor2
#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;
    for(itr=tail;itr != NULL;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;
}