India, Sept. 28 -- Like everything else, the way one collects movies has evolved. We have moved on from projector reels to cassettes to discs to the present, when everything is digital. Some store their films on hard disks and some online.

The following puzzle acknowledges the evolution by reflecting on the DVD age, which we left behind a decade or so ago.

# Puzzle 214.1

A film buff and his wife, who shares his interest, have built a collection in digital format, and are now getting rid of physical media that take up more space than their house in Mumbai can afford.

"Sad to see those go," says the husband, pointing to six DVDs-two each of Rear Window, Roman Holiday and Sunset Boulevard.

"I didn't know we had two copies of each," his ...