#include <cstdio>
#include <unordered_set>

using namespace std;

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

  int N, op, x;
  unordered_set<int> hash;

  scanf("%d", &N);
  for (int i = 0; i < N; ++i) {
    scanf("%d%d", &op, &x);
    if (op == 1) {
      hash.insert(x);
      continue;
    }
    if (op == 2) {
      hash.erase(x);
      continue;
    }
    printf("%d\n", hash.find(x) != hash.end());
  }
  
  return 0;
}