Code to run to currently populated cells

Hi all

I am using the following code to insert two new columns and then put the weeknum and L2 in each, and then delete an unwanted cell, my question is that my data sped changes each week this week it had 198 next week it may only be 180 or 80 how do i change the code so it only goes as far as whats in cells C.
I am new to this and trying to learn as i go so any help would be good.

Thanks you.

Sub Line2()
'
' Line2 Macro
'

'
    Columns("A:B").Select
    Selection.Insert Shift:=xlToRight, CopyOrigin:=xlFormatFromLeftOrAbove
    Range("A2").Select
    ActiveCell.FormulaR1C1 = "=WEEKNUM(RC[2])"
    Range("A2").Select
    Selection.AutoFill Destination:=Range("A2:A198"), Type:=xlFillDefault
    Range("A2:A198").Select
    ActiveWindow.SmallScroll Down:=-219
    Range("B2").Select
    ActiveCell.FormulaR1C1 = "L2"
    Selection.AutoFill Destination:=Range("B2:B198"), Type:=xlFillCopy
    Range("B2:B198").Select
    ActiveWindow.SmallScroll Down:=-18
    Columns("F:F").Select
    Selection.Delete Shift:=xlToLeft
End Sub