#include <cstdio>
#include <algorithm>
#include <vector>
//#include <forward_list>

FILE* in = fopen("hashuri.in", "r");
FILE* out = fopen("hashuri.out", "w");

using namespace std;

vector <long> v;
//vector <vector<long>::iterator> rep;

short check (long x)
{
    /*
    vector<long>::const_iterator i = find(v.begin(), v.end(), x);

    if (i == v.end())
    {
        return 0;
    }

    return 1;
    */

    return binary_search(v.begin(), v.end(), x);
}

short add (long x)
{
    if (check(x) == 0)
    {
        v.push_back(x);
        return 0;
    }

    return 1;
}

short del (long x)
{
    vector<long>::iterator i = find(v.begin(), v.end(), x);

    if (i != v.end())
    {
        v.erase(i);
        return 0;
    }

    return 1;
}

int main()
{
    /* debug
     *add(3);
     *add(5);
     *add(10);
     *del(5);
     *add(15);
     *vector<long>::iterator i = v.begin();
     *for( ; i < v.end(); i++)
     *{
     *   fprintf(out, "%i ", *i);
     *}
     */

    v.reserve(1000000);
    long i = 0;
    short cmd = 0;
    long arg = 0;

    fscanf(in, "%li", &i);

    for (long y = 0; y < i; y++)
    {
        fscanf(in, "%hi %li", &cmd, &arg);

        switch (cmd)
        {
            case 1:
                add(arg);
                break;
            case 2:
                del(arg);
                break;
            case 3:
                //v.unique();
                fprintf(out, "%hi\n", check(arg));
                break;
            default:
                printf("ERROR: Unknown command %i!", cmd);
                break;
        }
    }

    fclose(in);
    fclose(out);

    return 0;
}