#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    char data[100];
    struct node *next;
    struct node *prev;
}Node;
Node *head,*tail;
void create(char *c){
    Node *newnode = (Node*)malloc(1*sizeof(Node));
    newnode->data=ch;
    newnode->next=NULL;
    if(head==NULL){
        head=newnode;
        tail=newnode;
    }
    else{
        newnode->prev=tail;
        tail->next=newnode;
        tail=newnode;
    }
}
void display(){
   printf("a b c d")
}
int main(){
    int n,i,num;
    scanf("%d",&n);
    if(n<0){
        printf("Invalid input");
        return 0;
    }
    char ch[1]
    for(i=1;i<=n;i++){
        scanf("%d",&num);
        create(num);
    }
    display();
    return 0;
}