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

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

int n, i, x, y;
set <int> s;

int main()
{
    fin>>n;
    for(i=0; i<n; i++)
    {
        fin>>x>>y;
        if(x == 1)
            s.insert(y);
        else
        {
            if(x == 2)
                s.erase(y);
            else
            {
                if(s.find(y) == s.end())
                    fout<<0<<'\n';
                else
                    fout<<1<<'\n';
            }
        }
    }

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