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

#ifndef DEBUG
#define DEBUG(...) printf(__VA_ARGS__)
#endif


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

void dodaj(node **head, node **tail, node **half, int val, *brelemenata){
  node *new;

  new = (node *) malloc(sizeof(node));

  if(!new) return;

  new->val = val;
  new->next = *head;
  new->prev = ;
  *head = new;

  (*brelemenata)++;
}

void obrisi(node **tail, *brelemenata){
  node *tmp;

  if(!*head) return;

  tmp = (*head)->next;
  free(*head);
  *head = tmp;

  (*brelemenata)--;

}

void polprvihnakraj(brelemenata){




}

int main() {
  int n, x, k, brelemenata = 0;
  char c;
  node *head = NULL, *tail = NULL, *half = NULL;

  scanf("%d", &n);

  for(int i = 0; i < n; ++i) {
    scanf("%c%d", &c, &x);

    if(c == 'd') {

    } else if(c == 'o') {

    } else if (c == 'p') {

    }
  }

  return 0;
}