#include <fstream>
#include <set>

using namespace std;

int N;
set<int> A;

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

    int op, x;

    for (fin >> N; N; --N)
    {
        fin >> op >> x;
        if (op == 1)
        {
            A.insert(x);
            continue;
        }
        if (op == 2)
        {
            A.erase(x);
            continue;
        }
        fout << (A.find(x) != A.end()) << '\n';
    }
    return 0;
}