#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

struct Element {
    int key;
    struct Element* link;
};

Element* hashTable[115249] = {nullptr};

void insert(int key) {
    int index = abs(key % 115249);
    Element* ptr = new Element();
    ptr->key = key;
    ptr->link = nullptr;
    if (hashTable[index] == nullptr) {
        hashTable[index] = ptr;
    }
    else {
        Element* ptr1;
        ptr1 = hashTable[index];
        while (ptr1->link) {
            if (ptr1->key == key)
                return;
            ptr1 = ptr1->link;
        }
        if (ptr1->key != key)
            ptr1->link = ptr;
    }
}

void del(int key) {
    Element* ptr;
    int index = abs(key % 115249);
    ptr = hashTable[index];
    if (ptr == nullptr)
        return;
    if (ptr->key == key) {
        hashTable[index] = ptr->link;
        return;
    }
    while (ptr->link) {
        if (ptr->link->key == key) {
            ptr->link = ptr->link->link;
            return;
        }
        ptr = ptr->link;
    }
}

bool exists(int key) {
    Element* ptr;
    int index = abs(key % 115249);
    ptr = hashTable[index];
    if (!ptr) {
        return false;
    }
    if (ptr->key == key) {
        return true;
    }

    while (ptr->link) {
        if (ptr->key == key)
            return true;
        ptr = ptr->link;
    }
    return ptr->key == key;
}



int main() {
    ifstream fin("set.in");
    ofstream fout("set.out");
    string com;
    int key;
    while (fin >> com) {
        fin >> key;
        if (com == "insert")
            insert(key);
        else if (com == "delete")
            del(key);
        else if (com == "exists"){
            bool ex = exists(key);
            if (ex)
                fout << "true" << "\n";
            else
                fout << "false" << "\n";
        }
    }
    return 0;
}