Как найти произведение всех нечетных чисел первой сотни

Option Explicit
'произведение всех нечетных чисел первой сотни.
'умножение
Function mul(m1 As String, m2 As String) As String
Dim a() As String, n As Byte
Dim i1 As Long, i2 As Long, L1 As Long, L2 As Long
  L1 = Len(m1): L2 = Len(m2)
  ReDim a(L1 + L2)
  For i2 = L2 To 1 Step -1
    n = Mid$(m2, i2, 1)
    For i1 = L1 To 1 Step -1
      a(i1 + i2) = Val(a(i1 + i2)) + n * Mid$(m1, i1, 1)
      If a(i1 + i2) > 9 Then
        a(i1 + i2 - 1) = Val(a(i1 + i2 - 1)) + a(i1 + i2) \ 10
        a(i1 + i2) = a(i1 + i2) Mod 10
      End If
    Next i1
  Next i2
  mul = Join(a, "")
End Function
 
Sub main()
Dim i As Long, Res As String
Res = 1
For i = 3 To 99 Step 2
  Res = mul(Res, CStr(i))
Next i
MsgBox Res
End Sub