主题：这样的输入怎么实现?

Dim strs As String="1234567891011121314"

Dim s As String

For i As Integer=1 To strs.length   

    s=s & strs(i-1)

    If (i Mod 4) = 0 Then

     s= s & " "

    End If

Next

MessageBox.show(s)