#include <fstream>
#include <unordered_set>

using namespace std;
  
int main()
{
    ifstream in("hashuri.in");
    ofstream out("hashuri.out");
    unordered_set<int> set;
    int n, op, val;
    
    in >> n;
    while (n--)
    {
        in >> op >> val;
        switch (op)
        {
            case 1:
                set.emplace(val);
                break;
            case 2:
                set.erase(val);
                break;
            case 3:
                out << (set.find(val) != set.end()) << '\n';
                break;
        }
    }
}