#include <fstream>
#include <map>

using namespace std;

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

int n, op, x, cnt;
map<int, int> mp;

int main() {
    fin >> n;
    for (int i = 1; i <= n; i++) {
        fin >> op >> x;
        if (op == 1) {
            if (mp.find(x) == mp.end())
                mp[x] = ++cnt;
        } else if (op == 2) {
            mp.erase(x);
        } else {
            fout << (mp.find(x) != mp.end()) << '\n';
        }
    }

    return 0;
}