#include <fstream>
#include <set>

using namespace std;

unsigned int N, x;
unsigned short int op;

set <unsigned int> A;
unsigned int i;

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