merge 2 sorted array, C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public void MergeSortedList(Node first, Node second)
{
  //we would be adding node from second list to first list
  //If second node data id more than first one then exchange it
  if(first.data.ToString().compareto(second.data.ToString()) > 0)
  {
   node t = first;
   first = second;
   second = first;
  }
head = first;//Assign head to first Node
 
while ((first.next != null ) && (second != null))
{
     if (Convert.ToInt32(first.next.data.ToString())) < Convert.ToInt32(first.data.ToString()))
     {
     first = first.next;//iterate over the first node
     }
     else
     {
     Node n = first.next;
     Node t = second.next;
     first.next = second;
     second.next = n;
     first = first.next;
     second = t;
     }
}
if (first.next = null)
    {
    first.next =  second;
    }
    }
}

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