#include <bits/stdc++.h>

using namespace std;

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

map<int, int> M;
int N, NR;
int op, x;

int main()
{
    f >> N;
    for (int i = 1; i <= N; i++)
    {
        f >> op >> x;
        if (op == 1)
            M[x] = ++NR;
        if (op == 2)
            M.erase(x);
        if (op == 3)
            g << (M.find(x) != M.end()) << '\n';
    }

    f.close();
    g.close();
    return 0;
}