Excel VB Script to Enter Data based on whether a Cell is empty or not

Hello everyone...

I have to insert data into Column C of a spreadsheet based on whether Column A or B are empty or not.

Attached excel file "test1.xls" shows the output format as well as what i have so far in terms of macro and here is the code which I have so far..

Sub Macro2()

Dim X As Integer

Dim numb As Integer

X = 2

numb = 1

Dim strFile As String

Do
 
If Not IsEmpty("B" & X) Then
    If Not IsEmpty("A" & X) Then
       
            strFile = Trim(ActiveSheet.Range("A" & X).Value) + ".pdf"
            ActiveCell.Value = strFile

        numb = numb + 1
        
        If numb > 4 Then
            Exit Sub
        End If
 X = X + 1
    End If
    
  X = X + 1

 ActiveCell.Offset(1, 0).Select
 ActiveSheet.Range("C" & X).Select

End If

Loop
  
End Sub

basically, as you would notice that the first 2 entries in Column C match the desired output because the number of entries in Column B is only one. The moment there are more entries than one in Column B, I am unable to skip the rows eg. skipping rows from C6 to C10 in this case.

Any help in this regard is greatly appreciated...

Thanks all in advance :-)