#include <iostream>
#include <vector>
using namespace std;

const int MAX = 1e6 + 1;

struct HashSet
{
    vector <int> v[MAX];
    HashSet()
    {
        for (int i = 0; i < v->size(); ++i)
            v[i] = {};
    }
    int HashFunc(int x)
    {
        return (abs(x) % MAX);
    }
    bool exists(int x)
    {
        int hash = this->HashFunc(x);
        for (auto i : (this->v[hash]))
            if (i == x)
                return 1;
        return 0;
    }
    void insert(int x)
    {
        if (this->exists(x))
            return;
        v[HashFunc(x)].push_back(x);
    }
    void erase(int x)
    {
        if (!this->exists(x))
            return;
        int k = 0;
        for (int i = 0; i < v[HashFunc(x)].size(); ++i)
            if (v[HashFunc(x)][i] == x)
                k = i;
        swap(v[HashFunc(x)][k], v[HashFunc(x)][v[HashFunc(x)].size() - 1]);
        v[HashFunc(x)].pop_back();
    }

};


    int main()
{
        freopen("set.in", "r", stdin);
        freopen("set.out", "w", stdout);
        string str;
        int x;
        auto h = new HashSet();
        while (cin >> str)
        {
            cin >> x;
            if (str == "insert")
                h->insert(x);
            else if (str == "delete")
                h->erase(x);
            else if (str == "exists")
            {
                if (h->exists(x))
                    cout << "true" << '\n';
                else
                    cout << "false" << '\n';
            }
        }



    return 0;
}