#include <iostream>
#include <fstream>
#include <set>
using namespace std;
set <int> myset;
int n,c,x;
int main()
{
    ifstream f ("hashuri.in");
    ofstream g ("hashuri.out");
    f>>n;
    for (int i=1;i<=n;i++)
    {
        f>>c>>x;
        if (c==1)
            myset.insert(x);
        else if (c==2)
            myset.erase(x);
        else
        {
            set <int> :: iterator it=myset.find(x);
            if (it!=myset.end()) g<<1<<'\n';
            else g<<0<<'\n';
        }
    }
}