#include <bits/stdc++.h>

using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
set<int> S;
int n,o,x;
int main()
{
    f>>n;
    for(; n; n--)
    {
        f>>o>>x;
        if(o==1)
            S.insert(x);
        else if(o==2)
            S.erase(x);
        else
        {
            auto it=S.find(x);
            if(it==S.end())
                g<<"0\n";
            else
                g<<"1\n";
        }
    }
    return 0;
}