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

using namespace std;

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

int n, op, x;

set <int> v;

int main()
{
    for (f>>n; n; --n)
    {
        f>>op>>x;
        if (op==1)
        {
            v.insert(x);
            continue;
        }
        if (op==2)
        {
            v.erase(x);
            continue;
        }
        g<<(v.find(x)!=v.end())<<"\n";
    }
    return 0;
}