#include <fstream>
#include <unordered_set>
using namespace std;

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

unordered_set<int> us;

int main()
{
    int i, type, x, n;
    fin>>n;

    for(i = 1; i <= n; ++i){
        fin>>type>>x;

        if(type == 1){
            us.insert(x);
        }
        else if(type == 2){
            us.erase(x);
        }
        else{
            fout<<us.count(x)<<'\n';
        }
    }
    return 0;
}