#include <iostream>
#include <fstream>
#include <unordered_map>
using namespace std;

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

unordered_map <int,bool> H;

int main() {
    ios_base :: sync_with_stdio (false);
    int n, op, x, i;
    fin >> n;
    for (i = 1; i <= n; i++) {
        fin >> op >> x;
        if (op == 1) {
            H[x] = true;
        } else if (op == 2) {
            H.erase(x);
        } else {
            fout << (H.find(x) != H.end()) << "\n";
        }
    }
    fin.close();
    fout.close();
    return 0;
}