#include <iostream>
#include <fstream>
#include <unordered_set>

using namespace std;

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

int n, op, x;
unordered_set<int> A;
//
int main()
{
    fin >> n;
    for(int i = 1; i <= n; ++i) {
        fin >> op >> x;
        switch(op) {
            case 1 : A.insert(x); break;
            case 2 : A.erase(x); break;
            case 3 : fout << (A.find(x) != A.end()) << '\n'; break;
        }
    }
    return 0;
}