#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const int lengthArr = 80021; // 9973, 9629, 8699, 7013, 6949

ifstream in;
ofstream out;

struct node {
  struct node* prev;
  struct node* next;
  int key;
};

struct node* new_list() {
  node* x = (node*) malloc(sizeof(node));
  x->key = NULL;
  x->next = nullptr;
  return x;
}

struct node push_back (struct node** head, int value) {
  node* new_list = (struct node*)malloc(sizeof(node));
  new_list->key = value;
  (*head)->next = new_list;
  new_list->prev = *head;
  new_list->next = nullptr;
  *head = new_list;
}

struct node* search (struct node* head, int value) {
  struct node* cur = head;
  while (cur->next != nullptr && cur->key != value) {
    cur = cur->next;
  }
  return cur;
}

int pop(struct node **head) {
  node* prev = nullptr;
  int val;
  if (head == nullptr) {
    return NULL;
  }
  prev = (*head);
  val = prev->key;
  (*head) = (*head)->next;
  free(prev);
  return val;
}

struct node* Search(struct node* head, int key) {
  while (head->next != nullptr && head->key != key) {
    head = head->next;
  }
  return head;
}

void deleteN(struct node *head, int key) {
  struct node* find = head;
  struct node* point = Search(find, key);
  int var = NULL;
  if (point != nullptr && point->key == key) {
    printf ("i`m here1\n");
    if (point->next != nullptr)
      (point->next)->prev = point->prev;
    else if (point->prev != nullptr) {
      point->prev->next = nullptr;
    }
    printf ("i`m here2\n");
    if (point->prev != nullptr)
      (point->prev)->next = point->next;
    else if (point->next != nullptr) {
      point->next->prev = nullptr;
    }
    printf ("i`m here3\n");
    var = point->key;
    printf ("i`m here4\n");
    free(point);
    printf ("i`m here5\n");
  }
}

int hashFunction(int key) {
  int ans = 0;
  int mn = 1;
  while (key > 0) {
    ans += (key % 10) * mn;
    mn *= 17;
    key /= 10;
  }
  return ans % lengthArr;
}


int main() {
  in.open("set.in");
  out.open("set.out");
  struct node* arr[lengthArr];
  for (int i = 0; i < lengthArr; i++) {
    arr[i] = new_list();
  }
  string s;
  int ind = 0;
  while(in >> s) {
    int k;
    in >> k;
    int hash = hashFunction(k);
    if (s == "insert") {
      struct node* point = search(arr[hash], k);
      if (point->key != k) {
        push_back(&point, k);
      }
    }
    else if (s == "delete") {
      deleteN(arr[hash], k);
    }
    else {
      struct node* point = search(arr[hash], k);
      if (point->key != k)
        out << "false" << endl;
      else
        out << "true" << endl;
    }
  }
  return 0;
}