#include <iostream>
#include <fstream>
#include <map>
using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
map<int,int> h;
int n,t,x,i;
int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>t>>x;
        if(t==1&&!h.count(x)) h[x]=1;
        else if(t==2&&h.count(x)) h.erase(x);
        else if(t==3)fout<<h.count(x)<<"\n";
    }
    return 0;
}