#include <fstream>
#include <map>

#define mod 666013
using namespace std;

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

map <int, int> M;
int main()
{
    int n;
    int op, x;
    int nr = 0;
    fin >> n;
    for (; n; --n)
    {
        fin >> op >> x;
        if (op < 2 && (M.find(x) == M.end())) M[x] = ++nr;
        else if (op < 3) M.erase(x);
        else if (M.find(x) != M.end()) fout << 1 << '\n';
        else fout << 0 << '\n';
    }
    return 0;
}