using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

/**

 * Definition for singly-linked list.*/

  public class ListNode 

  {

      public int val;

      public ListNode next;

      public ListNode(int val=0, ListNode next=null) 

      {

          this.val = val;

          this.next = next;

      }

  }

public class Solution {

    public ListNode MergeKLists(ListNode[] lists) {

    }

}