Imports System.IO
Module CountTypes
    ' store strings and counts as hash table
    ' key = string itself
    ' value = number of times seen
    Dim table As New Hashtable
    ' add strings to hash table
    Sub Absorb(ByRef sr As StreamReader)
        Dim line As String
        While Not sr.EndOfStream
            line = sr.ReadLine()
            If line <> "" Then
                If table.Contains(line) Then
                    table.Item(line) += 1
                Else
                    table.Add(line, 1)
                End If
            End If
        End While
    End Sub
    ' main program
    Sub Main(ByVal Args() As String)

        ' check for command line arguments
        If Args.Length > 0 Then
            ' yes, treat them as files
            For i As Integer = 0 To Args.Length - 1
                Dim sr As StreamReader = New StreamReader(Args(i))
                Absorb(sr)
                sr.Close()
            Next
        Else
            ' no, read the standard input
            Dim sr As StreamReader = New StreamReader(Console.OpenStandardInput)
            Absorb(sr)
            sr.Close()
        End If

        ' dump the contents of the hash table
        Dim de As DictionaryEntry
        For Each de In table
            Console.WriteLine(de.Value & vbTab & de.Key)
        Next

    End Sub

End Module