Найти наибольшее количество подряд идущих букв

Function LongSeqLett(S As String) As String
   Max$ = ""
   Curr$ = ""
   For i% = 1 To Len(S)
        sym$ = Mid$(S, i%, 1)
        If (sym$ >= "a" And sym$ <= "z") Or (sym$ >= "A" And sym$ <= "Z") Then
           Curr$ = Curr$ + sym$
        Else
           If Len(Curr$) > Len(Max$) Then Max$ = Curr$
           Curr$ = ""
        End If
    Next i%
    LongSeqLett = Max$
End Function
 
Sub Test()
    A$ = "aaa565#avqqqqqqn2nmn^cvcvvc#ww"
    Debug.Print LongSeqLett(A$)
End Sub

For i% = 1 To Len(S) + 1

Function LongSeqLett(ByVal S As String) As String
   Max$ = ""
   Curr$ = ""
   S = S & " "
   For i% = 1 To Len(S)
        sym$ = Mid$(S, i%, 1)
        If UCase$(sym$) <> LCase$(sym$) Then
           Curr$ = Curr$ + sym$
        Else
           If Len(Curr$) > Len(Max$) Then Max$ = Curr$
           Curr$ = ""
        End If
    Next i%
    LongSeqLett = Max$
End Function

Function LongSeqLetter$(ByVal txt$)
    Dim m$, i&, k&, l&, mxk&, mxl&
    txt = txt & " "
    For i = 1 To Len(txt)
        Select Case Asc(Mid$(txt, i, 1))
        Case 65 To 90, 97 To 122, 168, 184, 192 To 255: l = l + 1
        Case Else
            If l > mxl Then mxk = k: mxl = l
            l = 0
            k = i
        End Select
    Next i
    LongSeqLetter = Mid$(txt, mxk + 1, mxl)
End Function

Sub test()
    Const n& = 1000000
    Const sTxt$ = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzАБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯабвгдеёжзийклмнопрстуфхцчшщъыьэюя .,!?"
    Dim i&, txt$
    txt = Space(n)
    Randomize
    For i = 1 To n
        Mid$(txt, i, 1) = Mid$(sTxt, Int(Rnd * Len(sTxt) + 1), 1)
    Next i
    
    t = Timer
    Debug.Print LongSeqLetterULCase(txt), Timer - t
    t = Timer
    Debug.Print LongSeqLetterLike(txt), Timer - t
    t = Timer
    Debug.Print LongSeqLetterSelectCase(txt), Timer - t
    
End Sub
 
Function LongSeqLetterULCase$(txt$)
    Dim i&, k&, l&, mxk&, mxl&, Utxt$, Ltxt$
    Utxt = UCase$(txt)
    Ltxt = LCase$(txt)
    For i = 1 To Len(txt) + 1
        If Mid$(Utxt, i, 1) <> Mid$(Ltxt, i, 1) Then
           l = l + 1
        Else
            If l > mxl Then mxk = k: mxl = l
            l = 0
            k = i
        End If
    Next i
    LongSeqLetterULCase = Mid$(txt, mxk + 1, mxl)
End Function
 
Function LongSeqLetterLike$(txt$)
    Dim i&, k&, l&, mxk&, mxl&
    For i = 1 To Len(txt) + 1
        If Mid$(txt, i, 1) Like "[A-Za-zА-яЁё]" Then
           l = l + 1
        Else
            If l > mxl Then mxk = k: mxl = l
            l = 0
            k = i
        End If
    Next i
    LongSeqLetterLike = Mid$(txt, mxk + 1, mxl)
End Function
 
Function LongSeqLetterSelectCase$(ByVal txt$)
    Dim i&, k&, l&, mxk&, mxl&
    txt = txt & " "
    For i = 1 To Len(txt)
        Select Case Asc(Mid$(txt, i, 1))
        Case 65 To 90, 97 To 122, 168, 184, 192 To 255: l = l + 1
        Case Else
            If l > mxl Then mxk = k: mxl = l
            l = 0
            k = i
        End Select
    Next i
    LongSeqLetterSelectCase = Mid$(txt, mxk + 1, mxl)
End Function

Function LongSeqLetterArray$(txt$)
    Dim i&, k&, l&, mxk&, mxl&, atxt() As Byte
    atxt = StrConv(txt, vbFromUnicode)
    For i = 0 To UBound(atxt)
        Select Case atxt(i)
        Case 65 To 90, 97 To 122, 168, 184, 192 To 255: l = l + 1
        Case Else
            If l > mxl Then mxk = k: mxl = l
            l = 0
            k = i
        End Select
    Next i
    LongSeqLetterArray$ = Mid$(txt, mxk + 2, mxl)
End Function

atxt = StrConv(txt & " ", vbFromUnicode)

Function LongSeqLetterArray$(txt$)
    Dim i&, k&, l&, mxk&, mxl&, atxt() As Byte
    atxt = StrConv(txt & " ", vbFromUnicode)
    For i = 0 To UBound(atxt)
        Select Case atxt(i)
        Case 65 To 90, 97 To 122, 168, 184, 192 To 255: l = l + 1
        Case Else
            If l > mxl Then mxk = k: mxl = l
            l = 0
            k = i + 1
        End Select
    Next i
    LongSeqLetterArray = Mid$(txt, mxk + 1, mxl)
End Function