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

using namespace std;

std::ifstream input("set.in", std::ios_base::in);
std::ofstream output("set.out", std::ios_base::out | std::ios_base::trunc);

struct HashTable {
    HashTable() {
        hastTable.assign(SIZE + 3, vector<int>(0)); // 3 про запас, лень думать
    }

    int getHash(int value) {
        long a = value * 113 + 145861;
        a %= 6130667;
        a %= SIZE;
        return abs(a);
    }

    void insert(int value) {
        if (!contains(value)) {
            int hash = getHash(value);
            hastTable[hash].push_back(value);
        }
    }

    bool contains(int value) {
        int hash = getHash(value);
        if (!hastTable[hash].empty()) {
            for (int i : hastTable[hash]) {
                if (i == value) {
                    return true;
                }
            }
        }
        return false;
    }

    void remove(int value) {
        if (contains(value)) {
            int hash = getHash(value);
            for (int &i : hastTable[hash]) {
                if (i == value) {
                    i = 1000001;
                }
            }
        }
    }

    const int SIZE = 987911;
    vector<vector<int>> hastTable;
};

int main() {
    string command;
    int value;
    HashTable hashtable;
    while (input >> command) {
        input >> value;
        if (command == "insert") {
            hashtable.insert(value);
        } else if (command == "exists") {
            output << (hashtable.contains(value) ? "true" : "false") << "\n";
        } else if (command == "delete") {
            hashtable.remove(value);
        }
    }
}