#include<stdio.h>
#include<stdlib.h>
struct node{
    int data;
    struct node*next;
};
struct node*createnode(int data){
    struct node*newnode=(struct node*)malloc(sizeof(struct node));
    newnode->data=data;
    newnode->next=NULL;
    return newnode;
}
int main()
int n;
if(scanf("%d",&n)!=1)){
    printf("Invalid input");
    return 0;
}
if(n<0||n>10)
{
     printf("Invalid input");
    return 0;
struct node*head=NULL;
struct node*tail=NULL;
for(int i=0;i<n;i++){
    int x;
    if(scanf("%d",&x)!=1||x<0||x<-1000||x>1000){
    printf("Invalid input");
    return 0;
    }
    struct node*newnode=createnode(x);
    if(head==NULL){
        head=newnode;
        tail=newnode;
    }else{
        tail->next=newnode;
        tail=newnode;
    }
}
struct node*temp=head;
while(temp!=NULL){
    printf("%d",temp->data);
    temp=temp->next;
}
return 0;
}