Did you solve it? Are you more sorted than a German elf at Christmas?

The answer to today's puzzle, in which it is confirmed that Guardian readers are less clever than German 13-year-olds

Earlier today I set you the following puzzle, from a Christmas quiz set by the German Mathematical Society. About 80 per cent of German 12 to 14-year-olds gave the correct answer.

Below are the first four prototypes of a machine designed by elves designed to sort presents by weight. Each machine sorts four presents at a time. The four presents are placed in the top, and then fall through the slides. Where two presents meet at a crossing, the lighter present goes to the left, and the heavier one goes to the right. This is repeated until all four presents are at the bottom.