Imports System
Imports System.Text.RegularExpressions
 
Public Class Test
	Public Shared Sub Main()
		Dim text As String = "This is a very long string. Invoice Total: $1,399.52 Continuation of very long string."
    	Dim re As Regex = New Regex("Invoice Total:\s*\$(\d+(?:,\d+)*(?:\.\d+)?)")
		Dim m As Match = re.Match(text)
        If m.Success Then
            Console.WriteLine(m.Groups(1).Value.Replace(",",""))
        End If
	End Sub
End Class

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