#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
                    if(s.find(x)==s.end())
                        g<<"0\n";
                    else
                        g<<"1\n";
    }
    return 0;
}