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

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

set<int> m;
int n, x, c;

int main() {
    fin >> n;
    for (int i = 1; i <= n; i++) {
        fin >> c >> x;
        if (c == 1) {
            m.insert(x);
        } else if (c == 2) {
            m.erase(x);
        } else if (c == 3) {

            if (m.count(x)) {
                fout << 1<<endl;
            } else {
                fout << 0<<endl;
            }
        }
    }
    return 0;
}