#include<fstream>
#include<set>
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int n,op,nr;
set<int>a;
int main()
{
    f>>n;
    while(n)
    {
        n--;
        f>>op>>nr;
        if(op==1)
          a.insert(nr);
        else if(op==2)
          a.erase(nr);
        else
        {
            if(a.find(nr)!=a.end())
              g<<1<<"\n";
            else
              g<<0<<"\n";
        }
    }
    return 0;
}