#include <iostream>
#include <fstream>
#include <set>

using namespace std;

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

int n;
set<int>v;

int main()
{
    in>>n;
    int op;
    for(int i = 0; i < n; i++){
        int x;
        in>>op>>x;
        if(op == 1)
            v.insert(x);
        else if(op == 2)
            v.erase(x);
        else
            out<<(v.find(x) != v.end())<<"\n";
    }
    return 0;
}