Help with Sleeve instructions please

[Agfryckowska]

I am knitting my first jumper and am stuck on the sleeve instructions. I think I am getting dimmer as I move through the pattern!

What do I do with this?

****Place a marker at each end of last row.
Work 6 rows more in st-st.
Place a marker at each end of last row.
Cast off 9 sts at beg of next 6 rows.
Cast off rem 9 sts.

I have already knitted the first part of the sleeve as per instructions not listed above (I understood those!).
What I don't understand is marking at end of last row - which last row?

Please help.
Ags