#include<stdio.h>
#include<stdlib.h>

typedef struct node {
    int data;
    struct node *next;
    struct node *prev;
}Node;

Node *head = NULL, *tail;

void create(int sum) {
    Node *newnode = (Node) malloc (1 * sizeof(Node));
    newnode->data = num;
    newnode->next = NULL;
    newnode->prev = NULL;
    if(head == NULL) {
        head = newnode;
        tail = newnode;
    }
    else {
        newnode->prev = tail;
        tail->next = newnode;
        tail = newnode;
    }
}
void delete() {
    Node *temp=head;
    while(temp->next!=NULL){
    temp=temp->next;
        
    }
    temp->prev->next=NULL;
    free(temp);
}
void display() {
    Node *itr;
    for(itr=head;itr!=NULL;itr=itr->next)
        printf("%d",itr->data);
    }
}
int main() {
    int num,size,itr;
    scanf("%d",&n);
    if(size<0){
        printf("Invalid input");
        return 0;
    }
    for(itr=1;itr<=size;itr++)
    {
        scanf("%d",&num);
        create(num);
    }
    display();
    printf("\n");
    delete();
    display();
}