#include <fstream>
#include <unordered_map>

using namespace std;

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

unordered_map<int, bool> Hash;
int n, x, y;

int main() {
        in >> n;
        for(int i = 1; i <= n; i++) {
                in >> x >> y;
                if(x == 1) {
                        Hash[y] = true;
                } else if(x == 2) {
                        Hash.erase(y);
                } else if(x == 3) {
                        out << (Hash.find(y) != Hash.end()) << "\n";
                }
        }
        return 0;

}