#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node *next;
    struct node *prev;
}s2;

s2 *head=NULL,*tail=NULL;
s2 *temp=NULL;

void create(int num){
    s2 *new=(s2*)malloc(sizeof(s2));
    new->data=num;
    new->prev=NULL;
    new->next=NULL;
    if(head==NULL){
        head=new;
        tail=new;
    }else{
        tail->next=new;
        new->prev=tail;
        tail=new;
    }
}

int delete(int val){
    s2 *temp=head;
    temp=head->next;
    head->prev=NULL;
    
    
}

void display(){
    s2 *i;
    for(i=head;i!=NULL;i=i->next){
        printf("%d ",i->data);
    }
}
int main(){
    int size,num;
    
    scanf("%d",&size);
    for(int i=1;i<=size;i++){
        scanf("%d",&num);
        create(num);
    }
    display();
    delete();
    display();
    
    return 0;
}