#include <cstdio>
#include <unordered_set>

using namespace std;

int main()
{
  freopen("hashuri.in", "r", stdin);
  freopen("hashuri.out", "w", stdout);

  int N;
  scanf("%d", &N);
  unordered_set<int> S;
  for (int i = 0; i < N; ++i) {
    int op, x;
    scanf("%d%d", &op, &x);
    if (op == 1) S.insert(x);
    if (op == 2) S.erase(x);
    if (op == 3) printf("%d\n",(int)S.count(x));
  }
  return 0;
}