using System;

using System.Linq;

using System.Xml.Linq;

​

public class Program

{

    public static void Main()

    {

        const string xml =

            @"<resource>

  <description>TTT</description>

  <title>TEST</title>

  <entity xmlns=""TdmBLRuPlUz.xsd"">

    <UzdProd>

      <row>

        <F_DAUDZ>50</F_DAUDZ>

        <BR_DAUDZ/>

        <DAUDZ>50</DAUDZ>

        <U_DAUDZ/>

        <NKODS>ST2.0_014_023</NKODS>

      </row>

    </UzdProd>

    <UzdMat>

      <row>

        <NKODS>SAG 2.0_014_150</NKODS>

        <NNOSAUK>Sagatave 2.0mm*0.14*150m</NNOSAUK>

        <PK_VIEN>1</PK_VIEN>

        <DAUDZ>0.077</DAUDZ>

        <F_DAUDZ>0.077</F_DAUDZ>

      </row>

    </UzdMat>

  </entity>

</resource>";

        XNamespace ns = "TdmBLRuPlUz.xsd";

​

        var doc = XDocument.Parse(xml);

​

        var prodRow = doc.Descendants(ns + "UzdProd").Elements(ns + "row").Single();

        var matRow = doc.Descendants(ns + "UzdMat").Elements(ns + "row").Single();

​

        var prodNkods = (string) prodRow.Element(ns + "NKODS");

        var matNkods = (string) matRow.Element(ns + "NKODS");

        Console.WriteLine($"Prod NKOS: {prodNkods}");

        Console.WriteLine($"Mat NKOS:  {matNkods}");      

    }

}