VBA looping

Can anyone tell me how to make it so the code works below for all worksheets?

Sub cutaneous()
N = Cells(Rows.Count, "A").End(xlUp).Row
Range("AM1").Formula = "=VLOOKUP(C2,Summary!A:C,3)"
Range("AM1").Copy Range("AM2:AM" & N)
End Sub

I tried:

Sub cutaneous()
Dim ws As Worksheet
   For Each ws In Worksheets
      With ws
    N = Cells(Rows.Count, "A").End(xlUp).Row
    End With
ws.Range("AM2").Formula = "=VLOOKUP(C2,Summary!A:C,3)"
ws.Range("AM2").Copy ws.Range("AM2:AM" & N)

   Next ws

End Sub

but this finds the range of the first sheet and uses that same range on every sheet