import java.util.*;

class Knowledge_base{
    ArrayList<String> Languages = new ArrayList<String>();
    ArrayList<String> Technologies = new ArrayList<String>();
    ArrayList<String> Databases = new ArrayList<String>();

    public void feats_unraveled() {                        //at the time of making
        Languages.add("Java");Languages.add("Python");Languages.add("C");Languages.add("C++");
    }
}

class Increased_knowledge extends Knowledge_base {
    @Override
    public void feats_unraveled() {
        super.feats_unraveled();
        Languages.add("HTML");Languages.add("CSS");Languages.add("Kotlin");
        Technologies.add("Git");Technologies.add("Machine Learning");
        Databases.add("MySQL");
        //_______.add("To be updated");
    }
}

class Vedeesh{
    public static void main(String[] args) {
        Knowledge_base obj = new Increased_knowledge();
        obj.feats_unraveled();
        System.out.println("Languages: "+obj.Languages);
        System.out.println("Technologies: "+obj.Technologies);
        System.out.println("Databases: "+obj.Databases);
    }
}