If you ever need to cut/copy/delete/paste lines without knowing the actual number of lines, here is what you should do.
- In normal mode, go to the beginning of the section that you want to yank.
mk to mark this spot as
- Go to the end of the section you want to yank using whatever movement commands you like.
y'k (y = yank, single quote = go to mark, k) To yank from the mark to the current location.
- You can paste those lines wherever you want with
d'k will cut/delete the lines from the current location to the mark.