#include <bits/stdc++.h>

using namespace std;
ifstream f("hash.in");
ofstream g("hash.out");
map <int,bool> M;
int main()
{
    int n,op,x;
    f>>n;
    while(n--)
    {
        f>>op>>x;
        switch (op)
        {
            case 1:{M[x]=1; break;}
            case 2:{M.erase(x); break;}
            case 3:{g<<bool(M.find(x)!=M.end())<<'\n'; break;}
        }
    }

    return 0;
}