combine values from multiple columns into a single cell in column

[parscon]

I need a VBA code that can combine values from multiple columns into a single column that mean if i have a data on column A2-A3-A4-A30-AA-AB... combine all of them into A1 i have this VBA code but it is not work on my data, because the column A is empty . i attached a sample file enclosed this post.

Thank you for your help

Sub Comb() 
Dim i As Long 
For i = 1 To Range("A" & Rows.count).end(xlup).row Step 1 
    For x = 2 To 256 
    If Cells(i, x).Value = "" Then 
    Else 
    Cells(i, 1).Value = Cells(i, 1).Value & ", " & Cells(i, x).Value 
    End If 
    Next x 
Next i 
End Sub