#include <fstream>
using namespace std;
ifstream fin ("hashuri.in");
ofstream fout ("hashuri.out");
struct nod {
    int info;
    nod *urm;
}*p;
int n,x,t;

int rez(nod * & p, int x){
    nod *r,*i;

    for(i=p;i->urm!=NULL && i->urm->info!=x;i=i->urm);
    if(t==1){
        if(i->urm==NULL){
            r=new nod;
            r->urm=NULL;
            r->info=x;
            i->urm=r;
        }
    }
    else
        if(t==2){
            if(i->urm!=NULL){
                r=i->urm;
                i->urm=i->urm->urm;
                delete(r);
            }
        }
        else
            return (i->urm!=NULL);
}
int main () {
    fin>>n;
    for(int i=1;i<=n;i++){
        fin>>t>>x;
        fout<<rez(p,x)<<"\n";
    }
}