#include <bits/stdc++.h>

using namespace std;

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

int main() {
    
    int n;
    f >> n;
    int op, x;
    set <int> s;
    
    for (int i = 1; i <= n; i++) {
        f >> op >> x;
        if (op == 1) {
            s.insert(x);
        } else if (op == 2) {
            s.erase(x);
        } else if (op == 3) {
            if (s.find(x) != s.end()) {
                 g << 1 << "\n";
            } else {
                 g << 0 << "\n";
            }
        }
    }
    
    

    return 0;
}