#include <fstream>
#include <ext/hash_set>
using namespace std;
ifstream fi("hashuri.in");
ofstream fo("hashuri.out");
__gnu_cxx::hash_set<unsigned>h;
unsigned n,x;int op;
int main() {
    f>>n;
    for(;n;n--) {
        f>>op>>x;
        switch(op) {
            case 1:h.insert(x);break;
            case 2:h.erase(x);break;
            case 3:fo<<(h.find(x)!=h.end())<<'\n';}}}