#include <fstream>
using namespace std;
#include <set>
set < int > s;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int n,i,y,x;
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<<endl;
                else
                    fout<<1<<endl;
            }

        }

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