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

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

unordered_set<int>multime;

int main()
{
    int n;
    in>>n;
    for(int k=0;k<n;k++)
    {
        int op, x;
        in>>op>>x;
        switch(op)
        {
        case 1:
            multime.insert(x);
            break;
        case 2:
            multime.erase(x);
            break;
        case 3:
            auto it = multime.find(x);
            out<<(it!=multime.end())<<'\n';
            break;
        }
    }
    return 0;
}