#include <fstream>
#include <set>

using namespace std;
set<int> s;
set<int>::iterator it;

int T, t, v;

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

    for (fin>>T;T;T--) {
        fin>>t>>v;
        if (t == 1)
            s.insert(v);
        else
            if (t == 2)
                s.erase(v);
            else {
                if (s.find(v) != s.end())
                    fout<<"1\n";
                else
                    fout<<"0\n";
            }
    }

    return 0;
}