#include <iostream>
#include <unordered_set>
#include <fstream>

using namespace std;

ifstream fin("hashuri.in");
ofstream fout("hashuri.out");

std::unordered_set<int> s;
int n,x,c;

int main()
{
    fin>>n;
    for(int i=1;i<=n;i++){
        fin>>c>>x;
        if(c==1)    s.insert(x);
        if(c==2)    s.erase(x);
        if(c==3)    fout<<s.count(x)<<'\n';
    }
    return 0;
}