#include <fstream>
#include <unordered_set>

using namespace std;

ifstream f("hashuri.in");
ofstream g("hashuri.out");

int x, nrquiz, type;
unordered_set < int > s;

int main()
{
    f >> nrquiz;

    while (nrquiz)
    {
        nrquiz --;

        f >> type >> x;

        if (type == 1)
            s.insert(x);

        if (type == 2)
            s.erase(x);

        if (type == 3)
            g << (s.find(x) != s.end()) << '\n';
    }
    return 0;
}