#include <fstream>
#include <set>

using namespace std;
ifstream cin("hashuri.in");
ofstream cout("hashuri.out");
set <int> S;
int main()
{
    int n,a,b;
    cin>>n;
    for(int i=1; i<=n; i++)
    {
        cin>>a>>b;
        if(a==1)
        {
            S.insert(b);
        }
        else if(a==2)
        {
            S.erase(b);
        }
        else
        {
            if(S.find(b)!=S.end())
                cout<<1;
            else
                cout<<0;
            cout<<'\n';
        }
    }
    return 0;
}