#include <cstdio>
#include <unordered_set>
using namespace std;
int n;
unordered_set<int> H;

void solve() {
  scanf("%d", &n);
  H.reserve(n);
  
  int type, x;
  for (int i = 1; i <= n; i++) {
    scanf("%d%d", &type, &x);
    switch (type) {
      case 1: {
        H.insert(x);
        break;
      }
      case 2: {
        H.erase(x);
        break;
      }
      case 3: {
        printf("%d\n", (int)H.count(x));
        break;
      }
    }
  }
}

int main() {
  freopen("hashuri.in", "r", stdin);
  freopen("hashuri.out", "w", stdout);
  
  solve();
  return 0;
}