#include <fstream>
#include <set>

using namespace std;

set<int> kkt;

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

int n,op,x;

int main()
{
    f >> n;
    for(int i = 1; i <= n; ++i)
    {
        f >> op >> x;

        if(op == 1) kkt.insert(x);
        if(op == 2) kkt.erase(x);
        if(op == 3) g << (kkt.find(x) != kkt.end()) << "\n";
    }

    return 0;
}