/* Online C# Compiler and Editor */

using System.IO;

using System;

​

public class ListNode<T>

{

    public T Value;

    public ListNode<T> Next;

​

    public ListNode(T value)

    {

        this.Value = value;

    }

}

​

public class List<T>

{

    public ListNode<T> Head;

​

    public List(ListNode<T> head)

    {

        Head = head;

    }

​

    public void ChangeListNodeValueById(int id, T value)

    {

        int k = 0;

        ListNode<T> node = this.Head;

        if (value != null)

        {

            while (node != null)

            {

                if (k == id)

                {

                    node.Value = value;

                }

                else

                {

                    node = node.Next;

                }

                k++;

            }

        }

    }

​

    public void merge(List<T> l2)

    {

        ListNode<T> node = this.Head;

        if (node != null)

        {

            while(node.Next != null)

            {

                node = node.Next;

            }

        }

        if (l2.Head != null)

        {

            node.Next = l2.Head;

        }

    }

}

​

public class TestProg

{

    public static void Main(string[] args)

    {

        ListNode<int> node = new ListNode<int>(25);

        ListNode<int> node2 = new ListNode<int>(56);

        node.Next = node2;

​

        ListNode<int> node3 = new ListNode<int>(2);

        ListNode<int> node4 = new ListNode<int>(1);

        node3.Next = node4;

​

        List<int> list = new List<int>(node);

        List<int> list2 = new List<int>(node3);

​

        ListNode<int> testNode = list.Head;

        while(testNode != null)

        {

            Console.WriteLine(testNode.Value);

            testNode = testNode.Next;

        }

​

        list.ChangeListNodeValueById(0, 30);

​

        testNode = list.Head;

        while (testNode != null)

        {

            Console.WriteLine(testNode.Value);

            testNode = testNode.Next;

        }

​

        list.merge(list2);

​

        testNode = list.Head;

        while (testNode != null)

        {

            Console.WriteLine(testNode.Value);

            testNode = testNode.Next;

        }

    }

}