#include <bits/stdc++.h>
using namespace std;
ifstream in("hashuri.in");
ofstream out("hashuri.out");
unordered_set<int> h;
int main()
{
    int q;
    for(in>>q;q;q--)
    {
        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;
}