They have a story book, a *** 18. If you want them to be as many as they are now. That is to say, everyone should have 18 ÷ 2 = 9 copies, and Lili gave Ningning 5 copies, as many as them. It shows that Ningning originally had 9-5 = 4 copies, while Lili originally had 18-4 = 14 copies.

The positive solution is as follows:

Ningning:

18 ÷ 2-5 = 9-5 = 4 (Ben)

He Lili:

18-4 = 4 (Ben)