#include <fstream>
#include <set>
using namespace std;

ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int n;
set<int> s;

int main()
{
    int op,x,i;
    set<int>::iterator it;
    fin>>n;
    for(i=1; i<=n; i++)
    {
        fin>>op>>x;
        if(op == 1)
        {
            s.insert(x);
        }
        else
        if(op == 2)
        {
            s.erase(x);
        }
        else
        {
            it = s.find(x);
            if(it != s.end()) fout<<1<<'\n';
            else fout<<0<<'\n';
        }
    }

    fin.close(); fout.close();
    return 0;
}