#include <fstream>
#include <unordered_set>
using namespace std;
ifstream fcin("hashuri.in");
ofstream fout("hashuri.out");
int q,x,c;
unordered_set <int> s;
int main()
{
    fcin>>q;
    while(q--)
    {
        fcin>>c>>x;
        if(c==1) s.insert(x);
        if(c==2) if(s.count(x)) s.erase(x);
        if(c==3) fout<<s.count(x)<<'\n';
    }
    return 0;
}