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

using namespace std;

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

    int n, op, x;
    unordered_set<int> m;
    fin>>n;
    while(n--){
        fin>>op>>x;
        if(op==1){
            m.insert(x);
            continue;
        }
        if(op==2){
            if(m.find(x)!=m.end())
                m.erase(x);
            continue;
        }
        fout<<(m.find(x)!=m.end())<<'\n';
    }

    return 0;
}