#include <fstream>
#include <set>

using namespace std;

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

    int n, op, number;
    f >> n;
    set<int> s;
    for (int i = 0; i < n; i++)
    {
        f>> op >> number;
        if (op == 1)
        {
            s.insert(number);
        }
        else if (op == 2)
        {
            s.erase(number);
        }
        else
        {
            int exista = s.find(number) != s.end() ? 1 : 0;
            g<< exista << "\n";
        }
    }

    return 0;
}