Unown Hash Function 2

Private Shared Function Hash(text As String) As Tuple(Of Int32, Int32)
    Dim charSet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789`~!@#$%^&*()_+-=|[];',.{}:<>? "
    Dim a As Int32 = 0
    Dim b As Int32 = 0
    For Each letter As var In text
        Dim e = charSet.IndexOf(letter)
        If e = -1 Then
            e = charSet.Length + 1
        End If
        For i As var = 0 To 16
            a = a * -6 + b + &H74fa - e
            b = b / 3 + a + &H81be - e
        Next
    Next
    Return Tuple.Create(a, b)
End Function