#include <fstream>
#include <unordered_set>
using namespace std;
unordered_set <int> v;
int n;
int main()
{
    ifstream f("hashuri.in");
    ofstream g("hashuri.out");
    int n;
    f >> n;
    int x, y;
    for (int i = 1; i <= n; ++i) {
        f >> x >> y;
    if (x == 1) v.insert(y);
       else if (x == 2) v.erase(y);
        else if (x == 3) {
            if (v.find(y)!=v.end()) g << 1 << "\n";
            else g << 0 << "\n";
        }
    }
    return 0;
}