#include <iostream>
#include <fstream>
#include <unordered_map>

using namespace std;

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

int n, nr, type, x;
unordered_map<int, int> m;

int main()
{
    f >> n;
    nr = 0;
    for(int i = 0; i < n; ++i)
    {
        f >> type >> x;
        if(type == 1 && m.find(x) == m.end())
            m[x] = nr++;
        if(type == 2)
            m.erase(x);
        if(type == 3)
            g << (m.find(x) != m.end()) << "\n";
    }
}