#include <bits/stdc++.h>

using namespace std;

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

int k, n, p, a;
unordered_set <int> m;

int main()
{
    in >> n;
    for (int i = 1; i <= n; ++i)
    {
        in >> p;
        if (p == 1)
        {
            in >> a;
            m.insert(a);
        }
        else if (p == 2)
        {
            in >> a;
            if (m.count(a))
                m.erase(a);
        }
        else
        {
            in >> a;
            out << (m.count(a)) << '\n';
        }
    }
    return 0;
}