#include<fstream>
#include<unordered_set>
using namespace std;
ifstream cin("hashuri.in");
ofstream cout("hashuri.out");
unordered_set<int> a;
int main()
{
    int n;
    for(cin>>n;n--;) {
        int i,j;
        if(cin>>i>>j,i==1)
            a.insert(j);
        else if(i==2)
            a.erase(j);
        else
            cout<<(a.find(j)!=a.end())<<'\n';
    }
    return 0;
}