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