#include<stdio.h>
#include<stdlib.h>
typedef struct Node{
int data;
struct Node*next;
}Node;
int main(){
int n,x;
if(scanf("%d",&n)!=1 ||n<=0){
printf("invalid input\n");
return 0;
}
Node *head = NULL,*tail=NULL,*p;
for(int i =0;i<n;i++){
    if (scanf("%d",&x)!=1){
        printf("invalid input\n");
        return 0;
    }
    p = malloc(sizeof(Node));
    p->data=x;p->next=NULL;
    if(!head)head=tail=p;
    else{tail->next=p;tail=p;}
    }
    for(p=head;p;p->next)printf("%d",p->data);
    printf("\n");
    return 0;
}