#include <bits/stdc++.h>
using namespace std;

set <int> H;
int main () {
    ifstream fin ("hashuri.in");
    ofstream fout ("hashuri.out");

    int n, key, x;
    fin >> n;
    for (; n; --n) {
        fin >> key >> x;
        switch (key) {
        case 1:
            H.insert(x);
            break;
        case 2:
            H.erase(H.find(x));
            break;
        case 3:
            fout << (H.find(x)!=H.end()) << '\n';;
            break;
        }
    }
    return 0;
}