include

include

include

include

include

include

using namespace std;

int main() { /* Enter your code here. Read input from STDIN. Print output to STDOUT */

int n;
cin>>n;

set<int> s;

while(n--){
    int a,b;
    cin>>a>>b;
    if(a==1){
        s.insert(b);
    }
    else if(a==2){
        s.erase(b);
    }
    else if(a==3){
        set<int>::iterator itr = s.find(b);
        if(itr!=s.end()){
            cout<<"Yes"<<endl;
        }
        else{
            cout<<"No"<<endl;
        }
    }
}

return 0;

}