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