using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ИнженерияЗнаний2
{
    class Tree
    {
        private class Node
        {
            public string text;
            public Node parent;
            public Node Yes;
            public Node No;
            public Node(string s)
            {
                text = s;
            }
        }
        Node root;
        Node itt;
        public Tree(string s)
        {
            root = new Node(s);
            itt = root;
        }
        public void SetYes(string s)
        {
            if (itt.Yes == null)
                itt.Yes = new Node(s)
                {
                    parent = itt
                };
            else itt.Yes.text = s;
        }
        public void SetNo(string s)
        {
            if (itt.No == null)
                itt.No = new Node(s)
            {
                parent = itt
            };

            else itt.No.text = s;
        }
        public void ToParent()
        {
            itt = itt.parent;
        }
        public void ToRoot()
        {
            itt = root;
        }
        public void SetText(string s)
        {
            itt.text = s;
        }
        public void ToYes()
        {
            itt = itt.Yes;
        }
        public void ToNo()
        {
            itt = itt.No;
        }
        public bool IsLeaf()
        {
            return itt.No == null && itt.Yes == null;
        }
        public bool IsRoot()
        {
            return itt.parent == null;
        }
        public string GetText()
        {
            return itt.text;
        }
        public void RemoveCurrent()
        {
            Node n = itt.parent;
            itt = null;
            itt = n;
        }

    }
}