#include <fstream>
#include <set>
using namespace std;

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