Sub Main()
Dim snum As String, num, s As Integer
Console.Write("Enter an odd number up to 13: ")
snum = Console.ReadLine
Integer.TryParse(snum, num)
If num Mod 2 = 0 Then num += 1 'verify odd number
If num > 13 Then num = 13 'restrict size to fit on screen
For x As Integer = 1 To num Step 2
s = (num + x) \ 2
Console.Write(Space(s))
For y As Integer = 1 To x
Console.Write("*")
Next y
Console.WriteLine()
Next x
For x As Integer = num - 2 To 1 Step -2
s = (num + x) \ 2
Console.Write(Space(s))
For y As Integer = 1 To x
Console.Write("*")
Next y
Console.WriteLine()
Next x
Console.ReadLine()
End Sub
End Module