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

using namespace std;

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

int n, c, x;
set <int> a;

int main()
{
    f>>n;

    for (int i=1; i<=n; i++)
    {
        f>>c>>x;

        if (c==1) a.insert(x);

        if (c==2) a.erase(x);

        if (c==3)
          if (a.find(x)!=a.end()) g<<1<<"\n";
          else g<<0<<"\n";
    }
    return 0;
}