#include<fstream>
#include<unordered_map>
using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int main()
{
    unordered_map<long long , bool> umap;
    int n,cer,x;
    fin>>n;
    for(int i=1;i<=n;i++)
    {
        fin>>cer>>x;
        if(cer==1)
        {
            umap[x]=1;
        }
        else if(cer==2)
        {
            if(umap.count(x)==1)
                umap.erase(x);
        }
        else
        {
            fout<<umap.count(x)<<"\n";
        }
    }
}