#include <cstdio>
#include <set>
using namespace std;
set<int>v;
int main(){
  freopen("hashuri.in", "r", stdin);
  freopen("hashuri.out", "w", stdout);
  int n, i, x, op;
  scanf("%d", &n);
  for (i = 1; i <= n; i ++){
    scanf("%d%d", &op, &x);
    if (op == 1)
      v.insert(x);
    else if (op == 2)
      v.erase(x);
    else
      printf("%d\n", v.find(x) != v.end());
  }
  return 0;
}