#include <iostream>
#include <fstream>
#include <vector>
#include <set>
using namespace std;
set<int>x;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int main()
{
    int n,a,b;
    fin>>n;
    for(int i=1;i<=n;i++)
    {
        fin>>a>>b;
        if(a==1&&x.count(b)==0) x.insert(b);
        if(a==2&&x.count(b)==1) x.erase(b);
        if(a==3)
        {
           fout<<x.count(b)<<"\n";
        }

    }
}