单项选择题

以下程序段运行的结果是______。
Dim a(-1 To 5) As Boolean
Dim flag As Boolean
flag = False
Dim i As Integer
Dim j As Integer
Do Until flag = True
For i=-1 To 5
j=j+1
If a(i)= False Then
a(i)= True
Exit For
End If
If i = 5 Then
flag = True
End If
Next
Loop
Print j