Poetry Competition; Riddle Guessing

Approaching a group of scholars, Gu Lan glanced inside and saw two young scholars bowing over two desks, writing something. One wore white, and the other wore black, seemingly engaged in a meaningful competition.

The surrounding scholars were all excited, staring without blinking as the two alternately wrote and paused.

"Brother, may I ask what they are doing?" Gu Lan asked a nearby scholar.

"They are engaged in a poetry competition. This is the most iconic activity in the literary meeting, where poetry is used to make friends, and everyone judges and determines the winner. Is this your first time here, brother? You seem unfamiliar with it," the scholar explained.

"Uh... Indeed, it's my first time!" Gu Lan felt a bit embarrassed to be labeled as a country bumpkin right after opening his mouth. He chose to remain silent and looked inside.