Wei Zi guessed the riddle.

Tang Yu, Shang Zhou and Hui all have mouths.

There are standing and sitting; Some run, others don't.

There are good people and no bad people; There are wise men, but no fools.

On the right, but not on the left; Eat and sleep.

Some are crying, some are laughing, some are alive and some are dead.

In Princess Zhu Huan, Swallow has a similar story: "There is no state ownership at home, no brother, and no Wei Zi."