#include <fstream>
#include <map>

using namespace std;
int x,tip,n;
map <int,int> m;
int main()
{
    ifstream fin("hashuri.in");
    ofstream fout("hashuri.out");
    fin>>n;
    while(n--)
    {
        fin>>tip>>x;
        if(tip==1) m[x]=n;
        else if(tip==2) m.erase(x);
        else fout<<(m.find(x)!=m.end())<<"\n";
    }
    fin.close();
    fout.close();
    return 0;
}