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

int main()
{
    ifstream f("hashuri.in");
    ofstream g("hashuri.out");
    int q;
    f >> q;
    unordered_set<int> s;
    for(int t, x; q; --q){
        f >> t >> x;
        if(t == 1) s.insert(x);
        else if(t == 2) s.erase(x);
        else g << (s.find(x) != end(s)) << '\n'; }
    return 0;
}