#include <fstream>
#include <unordered_set>
using namespace std;

int main()
{
    ifstream fin("hashuri.in");
    ofstream fout("hashuri.out");
    int n,op,x;
    unordered_set<int>S;
    fin>>n;
    while(n--)
    {
        fin>>op>>x;
        if(op==1 && S.find(x)==S.end())
            S.insert(x);
        if(op==2)
            S.erase(x);
        if(op==3)
            fout<<(S.find(x)!=S.end())<<'\n';
    }
    return 0;
}