#include <fstream>
#include <unordered_set>

using namespace std;

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

int n;
unordered_set<int> US;

void solve(){
    int op,x;
    in>>n;
    for(int i=1;i<=n;i++){
        in>>op>>x;
        if(op==1)
            US.insert(x);
        else if(op==2)
            US.erase(x);
        else out<<(US.find(x)!=US.end())<<"\n";
    }
}
int main(){
    solve();
    return 0;
}