Imports System

Imports System.Collections

Imports System.Collections.Generic

Imports System.Linq 

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Public Module Module1

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    Public Sub Main()

        dim recipientEmailAddresses as new ArrayList()

        Dim recipientSmsAddresses As New ArrayList()

        recipientEmailAddresses.Add("x@y.com")

        recipientEmailAddresses.Add("z@y.com")

        recipientSmsAddresses.Add("z@Y.com")

        recipientSmsAddresses.Add("zsms@Y.com")

        recipientEmailAddresses.AddRange(recipientSmsAddresses)

        Dim emails As New List(Of String) ()

        dim enumerator as IEnumerator = recipientEmailAddresses.GetEnumerator()

        while enumerator.MoveNext()

            emails.add(enumerator.Current)

        end while

        Dim final = New ArrayList(emails.GroupBy(Function(item as string) item, StringComparer.OrdinalIgnoreCase) _         

                    .Select(function(g) g.Key).ToArray())

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        For Each email as string in final

            Console.WriteLine(email)    

        next

    End Sub

End Module

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