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

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

set <int> s;

int main(){
    int n, op, x;
    fin >> n;
    for(int i = 1; i <= n; ++i){
        fin >> op >> x;
        if(op == 1)
            s.insert(x);
        else if(op == 2)
            s.erase(x);
        else {
            if(s.find(x) != s.end())
                fout << "1" << '\n';
            else fout << "0" << '\n';
        }
    }
    return 0;
}