#include<fstream.h>
#include<set>
using namespace std;
int N,K,x,y;
set<int> V;
int main()
{
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
fin>>N;
    for(int i=1;i<=N;++i)
    {
    fin>>x;
    if(x==1)
    {
    fin>>y;

    V.insert(y);
    }
    if(x==2)
    {
    fin>>y;
    V.erase(y);
    }
    if(x==3)
    {
        fin>>y;
        if(V.find(y)!=V.end())
           fout<<"1"<<"\n";
        else
        fout<<"0"<<"\n";
    }

    }
}