The last class was self-study. Chen Zhao buried himself in practice problems.
He had already run out of good problem sets. He'd finished all the ones he could get his hands on, so he downloaded a study app to his phone. It had all kinds of difficult problems, and he started working through them.
School rules forbade students from bringing phones, because the school worried they'd spend all their time playing instead of studying or use their phones to cheat. But the rules were only there to keep ordinary students in line. Chen Zhao was the top student in his grade, a top academic who'd advanced straight to the national finals in a competition. He was the school's prized pupil, the sort of student who made the principal smile whenever they met. Naturally, he could do as he pleased, bringing his phone to school every day. Even when teachers saw it, they didn't say anything.
The study app let users set the difficulty of the problems. There were five levels in total.
Easy.
Normal.
Hard.
Hell.
Ultimate Terror.
Five levels, each harder than the last.
At Chen Zhao's level, the easy problems wouldn't be worth his time, so he went straight for the highest level: "Ultimate Terror."
The app also had a PK feature for solving problems.
The PK feature paired you with another user working on problems at the same difficulty. You both got the same questions, and whoever had the higher accuracy and finished in less time won.
Since he was doing problems anyway, Chen Zhao turned on PK. Having a competitor could spur him on and remind him not to slack off. If he did, he'd lose, which would help him work more efficiently.
Each PK round had ten questions.
The first round began. They were all