#include <iostream>
#include <fstream>
#include <set>
using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");

int n,op,x,i;
set<int> v;

int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>op;
        fin>>x;
        if(op==1)
        {
            v.insert(x);
            continue;
        }
        if(op==2)
        {
            v.erase(x);
            continue;
        }
        if(v.find(x)!=v.end())
        {
            fout<<1<<"\n";
        }
        else
        {
            fout<<0<<"\n";
        }
    }
    fin.close();
    fout.close();
    return 0;
}