#include <bits/stdc++.h>
using namespace std;
ifstream in("hashuri.in");
ofstream out("hashuri.out");

unordered_set<int> h;
int main()
{
    int t;
    in>>t;
    while(t--)
    {
        int t,x;
        in>>t>>x;
        if
            (t==1)h.insert(x);
        else
            if
                (t==2)h.erase(x);
            else
                out<<(h.find(x)!=h.end())<<'\n';
    }
    return 0;
}