#include <unordered_set>
#include <fstream>

using namespace std;

ifstream in("hashuri.in");
ofstream out("hashuri.out");

unordered_set< int, hash<int> > H;

int main()
{
    int N, x, op;
    in >> N;
    for(int i = 1; i <= N; i++)
    {
        in >> op >> x;
        switch(op)
        {
        case 1:
            H.insert(x);
            break;
        case 2:
            H.erase(x);
            break;
        case 3:
            out << (H.find(x) != H.end()) << '\n';
            break;
        }
    }
    return 0;
}