#include <iostream>
#include <fstream>
#include <set>

using namespace std;

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

set<int> s;

int main() {
    int n;
    in >> n;
    for (int i{}; i < n; ++i) {
        int c;
        in >> c;
        if (c == 1) {
            int x;
            in >> x;
            s.insert(x);
            continue;
        }
        if (c == 2) {
            int x;
            in >> x;
            s.erase(x);
            continue;
        }
        if (c == 3) {
            int x;
            in >> x;
            if (s.find(x) != s.end()) {
                out << "1\n";
            }
            else {
                out << "0\n";
            }
            continue;
        }
    }
    return 0;
}