Imports System
Imports System.Text.RegularExpressions
 
Public Class Test
	Public Shared Sub Main()
            Console.WriteLine(ReplaceTime("[06:34:22] Hello there!"))
            Console.WriteLine(ReplaceTime("[22:47] Hi!"))
	End Sub
 
        Public Shared Function ReplaceTime(ByVal Input As String) As String
    Dim m As Match = Regex.Match(Input, "(\[)(\d{1,2}\:\d{1,2}(\:\d{1,2})?)(\])(.+)")
    Return m.Groups(1).Value & m.Groups(4).Value & m.Groups(5).Value
End Function
 
End Class

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