#include<fstream>
#include<unordered_set>
using namespace std;
ifstream cin("hashuri.in");
ofstream cout("hashuri.out");
int N,i,type,element,nr;
int main()
{
    cin>>N;
    unordered_set <int>M;
    for(i=1;i<=N;i++)
    {
        cin>>type>>element;
        if(type==1)
            M.insert(element);
        else if(type==2)
            M.erase(element);
        else
            cout<<(M.find(element)!=M.end())<<"\n";
    }
    return 0;
}