#include <iostream>
#include <fstream>
#include <set>
#include <cstdlib>
using namespace std;

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


int main() {
    char sir[20];
    int n, x, op;
    set<int> s;
    fin >> n;
    fin.get();
    for(int i=0; i<n; ++i)
    {
        fin.getline(sir, 20);
        op = sir[0]-'0';
        x = atoi(sir+2);
       // cerr << op << " " << x << endl;
        if(op == 1)
            s.insert(x);
        else if(op == 2)
            s.erase(x);
        else
        {
            if(s.find(x)!=s.end())
                fout << 1 << "\n";
            else
                fout << 0 << "\n";
        }


    }


    return 0;
}