#include <iostream>
#include <map>
using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
map <int, int> M;
int main()
{
int i, tip, x;
int N, NR;
fin>>N;
for (i = 1; i <= N; i++)
{
fin>>tip>>x;
if (tip == 1 && M.find(x)==M.end()) M[x] = ++NR;
if (tip == 2) M.erase(x);
if (tip == 3) fout<<'\n'<<M.find(x) != M.end();
}
return 0;
}