//This class is the main one which is used to act as a directory
class Node{
    protected String Name;
    protected int size;
    protected Node parent;
    protected Node child;
    protected Node next;
    protected String type;
    protected int access;
    protected int year,month,date,hour,minutes;

    //Constructor
    public Node(){

        Name="";
        parent=null;
        child=null;
        next=null;
        type="0";
        access=0;
        year=2002;
        month=10;
        date=2;
        hour=21;
        minutes=10;
    }
    //Constructor with various parameters being passed be written here

    //Is directory empty ?
    public boolean isEmpty(){
           return(next==null);
    }
    //Funcion to add subdirectory or file
    public void addChild(Node n)
    {     if(type.equalsIgnoreCase("dir"))
          {     if(size==0)
                {   child=n;
                    size++;
                }
                else
                {   Node temp;
                    boolean flag=true;
                    temp=child;
                    String old=temp.getName();
                    String add=n.getName();
                    while(temp!=null&&flag)
                    {   old=temp.getName();
                        if(!(old.equals(add)&&n.getType().equals(temp.getType())))
                        {  if(temp.getNext()==null)
                          {   temp.setNext(n);
                              size++;
                              flag=false;
                          }
                          else
                              temp=temp.getNext();

                        }
                        else
                              flag=false;
                    }
                }
            }
            else
                System.out.println("\nThis is not directory");
    }

   //Function to setChild
   public void setChild(Node n)
   {      child=n;
   }
   //Function to get the type of file or directory
    public String getType()
    {     return type;
    }
    //Function to set Name of file/directory
    public void setName(String s){
          Name=s;
    }
    //Function to get Child
    public Node getChild()
    {     return child;
    }
    //Function to get Parent of the directory
    public Node getParent()
    {     return parent;
    }
    //Function to get size
    public int getSize()
    {     return size;
    }
    //Function to get Name of directory
    public String getName(){
          return Name;
    }
    //Function to set size
    public void setSize(int n)
    {     size=n;
    }
    //Function to return path of the directroy
    public String getPath()
      {   String path=Name;
            Node temp=parent;
            while(temp!=null)
            {     path=temp.getName()+'/'+path;
                  temp=temp.getParent();
            }
            return path;
       }
}
//Many other function follow here involving getting date of last access and
//others.

//Write the class here that simulates the UNIX OS  involing a loop calling
//various methods discussed above and some others.