#include<fstream>
#include<ext/hash_set>
using namespace std;

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

__gnu_cxx::hash_set<unsigned> H;
unsigned N,x;
int op;
int main()
{
    f>>N;
    for(;N;N--)
    {
        f>>op>>x;
        switch(op)
        {
            case 1:H.insert(x);break;
            case 2:H.erase(x);break;
            case 3:g<<(H.find(x) != H.end())<<"\n";
        }
    }
}