#include <fstream>
#include <map>

using namespace std;

ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
int n;
map<int, int> m;

int main(){
    fin >> n;
    for(int i = 1; i <= n; i++){
        int c, x;
        fin >> c >> x;
        if(c == 1) if(m.count(x) == 0) m[x] = 1;
        if(c == 2) if(m.count(x) != 0) m.erase(x);
        if(c == 3) fout << m.count(x) << '\n';
    }
    fin.close();
    fout.close();
    return 0;
}