/* 
 * File:   main.cpp
 * Author: VirtualDemon
 *
 * Created on April 12, 2010, 4:23 PM
 */
#include <sstream>
#include <cstdlib>
#include <fstream>
#include <tr1/unordered_set>

/*
 * 
 */
using namespace std;
using namespace tr1;
unordered_set< int > s;
string ss;
int main(int argc, char** argv)
{
    int N, i, j;
    ifstream in( "hashuri.in" );
    ofstream out( "hashuri.out" );
    getline( in, ss, (char)EOF );
    istringstream ins( ss );
    ins>>N;
    for( ; N; --N )
    {
        ins>>i>>j;
        switch( i )
        {
            case 1 : s.insert(j); break;
            case 2 : s.erase(j); break;
            case 3 : out<<( s.end() != s.find(j) )<<'\n';
        }
    }
    return EXIT_SUCCESS;
}