#include <iostream>
#include <fstream>
#include <set>
#define MAXEL 2000000000

using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int main(){
    std::set<int> myset;
    int n;
    fin>>n;
    for(int i=1;i<=n;i++){
        int op,nr;
        fin>>op>>nr;
        if(op==1) myset.insert(nr);
        else if(op==2) myset.erase(nr);
        else{
            if(myset.find(nr)!=myset.end()) fout<<1;
            else fout<<0;
            fout<<'\n';
        }
    }
    return 0;
}