#include <bits/stdc++.h>

using namespace std;

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

int main(){
    int n , aux;
    set<int> s ;


    in >> n;

    for(int i = 0 ; i < n ; i ++ ){
        in >> aux;
        if(aux == 1) {
            in >> aux;
            s.insert(aux);
        }
        else if (aux == 2){
            in >> aux;
            s.erase(aux);
        }
        else{
            in >> aux;
            auto  it = s.find(aux);

            if (it != s.end()) {
                out << 1 << endl;
            } else {
                out << 0 << endl;
            }
        }

    }


    return 0;
}