#include <bits/stdc++.h>

using namespace std;

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

unordered_map<int, bool> S;

int main() {
    int n, t, a;
    fin>>n;
    while(n--) {
        fin>>t>>a;
        switch(t) {
            case 1: S[a] = 1; break;
            case 2: S.erase(a); break;
            case 3: fout<<(S.find(a) != S.end())<<'\n'; break;
        }
    }
    return 0;
}