#include <bits/stdc++.h>
using namespace std;
set<int>S;
set<int>::iterator it;
int op, x, gasit, nop;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int main()
{
    ios_base::sync_with_stdio(0);
    f.tie(0);
    g.tie(0);
    f >> nop;
    for(int i = 1; i <= nop; ++i)
    {
        f >> op >> x;
        if(op == 1)
        {
            S.insert(x);
        }
        if(op == 2)
        {
            S.erase(x);
        }
        if(op == 3)
        {
            it = S.find(x);
            if(it != S.end())
            {
                g << 1 << '\n';
            }
            else
            {
                g << 0 << '\n';
            }
        }
    }
    return 0;
}