using System;

public class BinNode<T> {

    private BinNode<T> left;

    private T value;

    private BinNode<T> right;

    public BinNode(T x) {

        this.left = null;

        this.value = x;

        this.right = null;

    }

​

    public BinNode(BinNode<T> left, T x, BinNode<T> right) {

        this.left = left;

        this.value = x;

        this.right = right;

    }

​

    public T getValue() {

        return this.value;

    }

​

    public void setValue(T x) {

        this.value = x;

    }

​

    public BinNode<T> getLeft() {

        return this.left;

    }

​

    public BinNode<T> getRight() {

        return this.right;

    }

​

    public void setLeft(BinNode<T> left) {

        this.left = left;

    }

​

    public void setRight(BinNode<T> right) {

        this.right = right;

    }

​

    public bool hasRight() {

        return this.right != null;

    }

​

    public bool hasLeft() {

        return this.left != null;

    }

​

    public override String ToString() {

        return this.value.ToString();

    }

}

public class Node<T>{

         private T value;

        private Node<T> next;

​

        // constructors:

        // O(1)

        public Node(T value) 

        {

            this.value = value;

            this.next = null;

        }

        // O(1)

        public Node(T value, Node<T> next) // 2

        {

            this.value = value;

            this.next = next;

        }

        // O(1)

        public T GetValue()

        {

            return this.value;

        }

        // O(1)

        public void SetValue(T value)

        {

            this.value = value;

        }

        // O(1)

        public Node<T> GetNext()

        {

            return this.next;

        }

        // O(1)

        public void SetNext(Node<T> next)

        {

            this.next = next;

        }

​

}

​

​

​

public class Program

{

    public static bool Exist(BinNode<int> t, int x){

        if(t == null){

            return false;

        }

        if(t.getValue()==x){

            return true;

        }

        return Exist(t.getLeft(),x) || Exist(t.getRight(),x);

    }

    public static Node<int> Check(BinNode<int> t1, BinNode<int> t2){

        Node<int> first = new Node<int>(-1);

        first = Check(t1,t2,first);

        return first.GetNext();

    }

    public static Node<int> Check(BinNode<int> t1, BinNode<int> t2, Node<int> list){

        if(t1!=null){

            if(!Exist(t2,t1.getValue())){

                list.SetNext(new Node<int>(t1.getValue(),list.GetNext()));

            }

            Check(t1.getLeft(), t2, list);

            Check(t1.getRight(),t2, list);

        }

        return list;

    }

    // סיבוכיות זמן ריצה O(n*m) 

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}