#include <bits/stdc++.h>

using namespace std;

class LinearProbing
{
public:

    LinearProbing()
    {
        table = new int[MAX_SIZE];

        for ( int i = 0; i < MAX_SIZE; ++i )
            table[i] = EMPTY;
    }

    ~LinearProbing()
    {
        delete[] table;
    }

    void insert(const int key)
    {
        int p = ((key & MOD) * PRIME) & MOD;

        while (table[p] != EMPTY && table[p] != ERASED)
            p = (p + 1) & MOD;

        table[p] = key;
    }

    bool find(const int key)
    {
        int p = ((key & MOD) * PRIME) & MOD;

        while (table[p] != EMPTY && table[p] != key)
            p = (p + 1) & MOD;

        return table[p] == key;
    }

    void erase(const int key)
    {
        int p = ((key & MOD) * PRIME) & MOD;

        while (table[p] != EMPTY && table[p] != key)
            p = (p + 1) & MOD;

        if (table[p] == key)
            table[p] = ERASED;
    }

private:

    static const int MAX_SIZE = 1 << 20;
    static const int MOD = MAX_SIZE - 1;
    static const int PRIME = 137;

    static const int EMPTY = -1;
    static const int ERASED = -2;

    int *table;
};

LinearProbing L;

int main()
{
    ifstream in("hashuri.in");
    ofstream out("hashuri.out");

    ios_base::sync_with_stdio( false );

    int N;
    in >> N;

    while ( N-- )
    {
        int tip, x;

        in >> tip >> x;

        switch(tip)
        {
            case 1: L.insert(x); break;
            case 2: L.erase(x); break;
            case 3: out << L.find(x) << "\n"; break;

            default: cerr << "Error\n";
        }
    }

    return 0;
}