#include <fstream>
#include <set>

using namespace std;

set<int> h;

int main()
{
    int i, n, x, op;
    ifstream fin("hashuri.in");
    ofstream fout("hashuri.out");
    fin >> n;
    for (i = 1; i <= n; ++i)
    {
        fin >> op >>x;
        if (op == 1) h.insert(x);
        else if (op == 2) h.erase(x);
        else if (h.find(x) == h.end()) fout << "0\n";
            else fout << "1\n";
    }
    fin.close();
    fout.close();

    return 0;
}