using System;

public class Program

{

    public static void Main()

    {

        var xml = @"<LogoutResponse 

        ID=""_f525259e-7e91-4282-9dc3-a0da65a4a17a"" 

        Version=""2.0"" 

        IssueInstant=""2021-05-17T15:41:55Z"" 

        InResponseTo=""_5089729f-5cc0-4a66-a3c1-e710cde92897"" 

        Destination=""https://idp.xyz/logout.aspx"" 

        xmlns=""urn:oasis:names:tc:SAML:2.0:protocol"">

        <Issuer xmlns=""urn:oasis:names:tc:SAML:2.0:assertion"">https://abc.xyz/api</Issuer>

        <Status>

            <StatusCode Value=""urn:oasis:names:tc:SAML:2.0:status:Success"" />

        </Status>

    </LogoutResponse>";

​

        var doc = new System.Xml.XmlDocument();

​

        doc.LoadXml(xml);

        var result = doc.SelectSingleNode("/LogoutResponse/Status/StatusCode/@Value").InnerText;

        Console.WriteLine(result);

    }

}