#include <iostream>
#include <fstream>
#include <map>
using namespace std;

int main() {
    ifstream cin("hashuri.in");
    ofstream cout("hashuri.out");
    map<unsigned int, bool> h;
    unsigned n, op, x;
    cin>>n;
    for (int i = 0; i < n; i++) {
        cin>>op>>x;
        if (op == 1) {
            h[x] = true;
        } else if (op == 2) {
            if (h.find(x) != h.end()) {
                h.erase(h.find(x));
            }
        } else {
            cout<<(h.find(x)!=h.end())<<"\n";
        }
    }
}