右框内划线处的内容可以是(    )

        PRIVATE SUB FORM_CLICK

        DIM A（4，4） AS INTEGER

        FOR I = 1 TO 4

           FOR J= 1 TO 4

              IF {#blank#}1{#/blank#}

                A（I，J）=1

              {#blank#}2{#/blank#}

               A（I，J）=0

              END IF

              PRINT A（I，j）;

              {#blank#}3{#/blank#}

            PRINT

              {#blank#}4{#/blank#}

        END SUB

PRIVATE SUB FORMCLICK

  FOR I = 3 TO {#blank#}1{#/blank#}

     F=0

     FOR J= 2 TO I-1

       IF {#blank#}2{#/blank#} THEN

        F=1

        EXIT FOR

       END IF

     NEXT J

  IF F=0   THEN {#blank#}3{#/blank#}

  {#blank#}4{#/blank#}

 END SUB

s=Text 1.Text：n=0：f=False

For i=1 To Len(s)

  ch=Mid(s，i，1) 

  If ch>="0" And ch<="9" Then

    If Not f Then

      f=True：n=n+1

    End If

  Else

    f=False

  End If

Next i

运行该程序段后，在文本框Text 1中输入“13+(123-23) *2”则变量n的值为（  ）