Add Uses to Group in Bulk using C#

So I had a task to take a list of usernames in a text document and add them to AD and map them to group(s). I am sure I could have done this quickly in Powershell, but I wanted to do it in C#. You can get the code here. The application is console based and uses some of our past AD classes.

The format was simple:

user1
user2
user3

A snippet of the code is below:

//using log4net;
//using ActiveDs;
public void Run()
       {
           foreach (AdUser user in ReadUsers())
           {
               using (user)
               {
                   Dictionary userGroups = GetUserGroupsDn(user.Entry);

                   foreach (string groupDn in _groupsToAddUserTo.Keys)
                   {
                       if (userGroups.ContainsKey(groupDn))
                           continue; // User already in this group
                      
                       AdGroup group = _groupsToAddUserTo[groupDn];

                       try
                       {
                           group.NativeObject.Add(user.Entry.Path);

                           log.Info(string.Format("User: {0} added to Group: {1}",
                           user.Entry.Properties["sAMAccountName"][0], group.NativeObject.Name));
                       }
                       catch (Exception)
                       {
                           log.Error(string.Format("User: {0} can't be added to Group: {1}. Possibly this is it's primary group already.",
                               user.Entry.Properties["sAMAccountName"][0], group.NativeObject.Name));
                       }
                   }
               }
           }
       }

...and main:

 private void Run(string[] args)
       {

//logging removed for brevity in snippet

           Settings settings = SettingsReader.ReadFromConfig();

           Adder adder = new Adder(settings);
           adder.UsersToProcess = ReadUsersToProcess(settings.UsersFilePath);
          
           adder.Run();
       }

Anyone want to show how this can be done in powershell in 25 or so lines?