KAIST Department of Mathematical Sciences, Professor’s Office.
Thud!
Thud!
Professor Kim Jiyun was sitting in her chair, banging her head against her desk.
Though only in her mid-thirties, she was already a globally recognized mathematician with unrivaled research achievements in the fields of combinatorics and design theory.
After earning her doctorate in combinatorial design theory, Professor Kim had gained international renown for her research on combinatorial structures over finite fields.
The number of citations her papers received in cryptography and statistics was nothing short of overwhelming, and she was also one of the very few candidates in Korea considered a future Fields Medal contender.
Her participation as a problem setter for the first round of this year’s KMO had not been a simple act of service.
Opportunities to observe mathematically gifted students from all over the country in one place did not come often.
Through the exam, she had intended to see whether there were any students with exceptional talent in her field. If they completed the answer sheet, perhaps someone would understand the message.
It was another hidden test, one that tested intuition, number sense, and logical ability.
But then…
“Aaaaargh! Who the hell ruined my work! Was it you?”
The teaching assistant, who had been hiding from her hysteria, flinched.
He was the one who had received the phone call about the answer change.
“Professor, I told you that wasn’t my fault. The Mathematical Society decided it.”
“Those damned old fogeys! Then they shouldn’t have left it to me in the first place! Why make me do it and then change it however they like?”
Still unable to calm her anger, she huffed and puffed as she picked up the phone and put it back down again.
“The committee said they couldn’t help it either. If the correct answer numbers are evenly distributed with five of each, there are always kids who count the numbers and guess, so they said at least one had to be changed.
And honestly, who would notice that? Everyone will be busy solving the problems, so they won’t even imagine there’s a hidden arrangement in the answers. There’s no way anyone could think of it just by looking at the numbers in the first place!”
Feeling wronged, the teaching assistant protested as he looked at the professor.
At that moment, he found himself pondering the correlation behind why all brilliant mathematicians seemed to be abnormal.
Was it because he was an extremely normal human being that his research had not been recognized? Then he would have to go mad, but this kind of madness was a problem.
Someone who could pass that perverted professor’s test…
“What if there is someone?”
“Pardon?”
“What if there’s a kid who recognizes it? How confused do you think they’d be? The answer that should obviously be number 1 is number 5! Do you know that pain? The agony of having to damage order with my own hands?”
He did not know any such thing.
The teaching assistant shook his head as if giving up.
“There won’t be anyone. No one. I guarantee it. Korean kids can’t do that kind of thing. All they do is solve past exam workbooks every day…”
The teaching assistant himself was from the KMO. He had even passed the second round.
Even at this university, there were first-round passers all over the place, so what was she talking about…? He was grateful for his respected professor’s overestimation, but he could state with certainty that such a thing would absolutely not happen.
“R-really?”
At the teaching assistant’s firm denial, the professor took a step back.
‘If they have talent in design theory, they should be able to see it, though.’
It was a trick she had set because she thought that if it were her, she would never miss it.
“Yes. If there is someone like that, Professor, bring them to our department. I’ll serve them as my senior.”
“Hmm…”
“Mr. Bak. Still, you know…”
“Yes.”
“If anyone completes the arrangement, let me know.”
“Completes it? Isn’t that impossible?”
Since the answer to problem 25 had already been changed to number 5, the probability that the Latin square Professor Kim had intended would appear had converged to zero.
Any student who got both the most difficult problem, number 23, and problem 4 correct would surely not get the comparatively easy final problem wrong. But complete the arrangement?
‘They’d have to get it wrong on purpose, wouldn’t they?’
“There is such a thing. There are worlds that children like you do not know.”
Looking at the teaching assistant’s face, full of questions, Professor Kim gave a slight chuckle and lightly patted him on the shoulder.
At that, the teaching assistant bristled.
“There you go again. I was the genius of Nowon-gu, Bak Hyeongju, you know? Back then, there wasn’t a person in the Junggye-dong academy district who didn’t know me. My mother was so proud of me… If she knew I was being treated like this in the lab, she would cry.”
“That’s why I’m asking why you came to graduate school. You should have gone to medical school or gotten a good job somewhere.”
The teaching assistant pouted and grumbled under his breath so she would not hear.
He liked cryptography and wanted to study it more, and yet she said he had no talent… But when he looked at his advisor’s achievements, he had no choice but to acknowledge it.
Even so, the reason he continued studying was because, in any case, not a single student had ever satisfied that professor. Was that why she had said she would write the KMO problems herself?
Sip.
Professor Kim, who had barely calmed herself, drank her coffee.
‘Ah, I hope there is someone.’
At first, she had been angry at the Mathematical Society for ruining her arrangement, but on second thought, she wondered if this might be an opportunity. If there was still someone who made a Latin square with the answers despite all this, then that person would truly be properly insane.
“Right. People who don’t understand mathematical aesthetics are hopeless no matter what they do.”
“Pardon?”
“No, not you.”
The teaching assistant seriously contemplated whether he should flee this lab.
* * *
Seoha came out after finishing the exam with a refreshed expression.
‘The cutoff won’t be a problem anyway.’
To Seoha, peace of mind was far more important than a perfect score.
The answer sheet he had completed was a beautiful form without a single flaw. The fact that one answer was wrong was, to him, nothing more than an extremely trivial issue.
“Seoha!”
Uhyeon waved from in front of a flashy sports car that did not suit the neighborhood.
“Teacher! What brings you here?”
When Seoha spotted him, he ran over happily.
“Your father said he was busy today, right? I came to pick you up instead.”
Seoha, who had been planning to take the bus, brightened.
He had been in a difficult position because the buses were infrequent.
“Get in.”
Uhyeon opened the car door for him.
Perhaps because foreign cars were unfamiliar to him, Seoha looked around the inside of the car with curiosity.
Vroooom—
Thinking of his passenger, Uhyeon stepped on the accelerator as gently as possible.
“How was the exam? It was easy for you, right?”
In truth, he was curious about the result.
That was also why he had volunteered to pick him up today.
There was no room to doubt Seoha’s mathematical ability, but because he so often did bizarre things, Uhyeon simply could not feel at ease.
“Hmm…”
When Seoha’s reaction was lukewarm, Uhyeon’s brow furrowed.
“What now?”
It was multiple choice, so there should have been no room for mistakes. What was with this halfhearted attitude?
“No. I think I did well.”
Seoha glanced at Uhyeon’s expression, then mumbled vaguely. Then he subtly turned his eyes and looked out the window.
“What do you mean, you think? You’re not the kind of kid who uses ambiguous expressions like that.”
“I got one wrong, but I have no regrets.”
“What is that supposed to mean?”
“Should I say it was worth getting wrong?”
“Ah! Seriously!”
Uhyeon clicked his tongue. But soon after, he wore an expression as if he had attained enlightenment.
“Fine. What’s the point of me saying anything? I’ll just have to trust you. You must have had a reason.”
Seoha looked at Uhyeon and nodded silently.
Perhaps because many people were enjoying the weekend afternoon, there were many cars on the road.
“If you got one wrong, passing the first round won’t be an issue. We can talk slowly later about why you did that. How was the difficulty?”
“Hmm… I think someone like Sujeong noona could get them all right.”
“She’s not on your level, but she was always famous too. If it’s about that level, then it should be fine.”
“They said there’s a training camp after the second round, right?”
Seoha was already worried about being apart from his younger sibling. She would be very upset…
“Yeah, because you’ll have to prepare for the third-round exam. By the way, can you speak any English?”
Seoha was startled by the sudden question.
“Pardon? I have no problem reading it, but why do you ask?”
“Next year’s competition is in England. All the participants stay in accommodations in the same building. If you know how to speak English, it’ll help in a lot of ways.”
“I’m not confident speaking. The only foreigners I’ve ever met are the native-speaking teachers who come by once in a while… Still, wouldn’t written communication be possible? Even if I’m not fluent, I think I’d be able to get the meaning across.”
“Everyone’s bad at it, so it’s fine.”
“If hundreds of people gather from a hundred countries, it must be incredibly fun.”
For Seoha, who had studied in a classroom with fewer than twenty students in one class, even that was something to look forward to a great deal.
But Uhyeon shook his head.
“You think so?”
“Is it not?”
“Think about it. The kids who go there are mostly guys who think they’re the greatest in the world. It’s full of unpleasant things.”
“Hahaha!”
“This isn’t something to laugh about. Do you think they’ll leave you alone just because you can’t communicate? There are plenty of other ways to show off your brain, aren’t there?”
“Uh… Surely they wouldn’t go that far.”
“Don’t underestimate teenagers packed full of ego and narcissism. Come to think of it, you’re strangely lacking in that. No, is yours actually excessively strong?”
Uhyeon tilted his head.
He had watched Seoha since he was very young, but he still did not fully understand him.
“Anyway, there are all sorts of games—mental arithmetic battles, Nim, Dots and Boxes, solving Rubik’s Cubes, and so on. People from all over will rush at you trying to beat you.”
“I know mental arithmetic battles and cubes, but I’ve never heard of the others.”
“The rules are simple. Even if you don’t practice separately, you’ll be good at them after trying once or twice. But the real major event is something else.”
“What is it?”
“Chess.”
“That’s unfair.”
“I think so too. If it were go, Korea, China, and Japan would be overwhelming. Still, chess is intuitive, and everyone knows the rules.”
“Did you play too, Teacher?”
Uhyeon sighed.
“There’s an unofficial chess tournament held during the IMO.
I was fairly strong, but I lost to a Russian kid in the quarterfinals. Since that guy ended up winning, I don’t really have any complaints, but I absolutely hated how smug he was.”
“It’s just chess, though?”
“That’s not the atmosphere. That’s also very much a competition between countries.
In Russia, Eastern Europe, and Europe, chess is a national sport. There are a lot of tournaments, and the prize money is big too. The guy who beat me was the Russian high school champion.”
“Then I can just play moderately like you and lose.”
At Seoha’s unmotivated appearance, Uhyeon bristled.
“This won’t do. You should learn chess right away.”
“Pardon? Now?”
“Yes. Think about it.
Let’s say that later, you become an incredibly great mathematician and solve a Millennium Problem. But then some Russian bum comes out on TV and gives an interview saying, ‘Yu Seoha wasn’t much. He was no match for me at chess.’”
Seoha grimaced.
“That would be a bit unpleasant.”
“Right?”
Screeeech—
Uhyeon hastily turned the car around.
The place they arrived at was a large bookstore in Daejeon that Seoha had been to before.
There, Uhyeon bought a chess manual for professional players and a high-end chess set.
“Now! Try beating me first. I may not look it, but I’m from a chess club, so I won’t be easy.”
On the way home, Seoha skimmed through the chess manual in the car. Then he gave a faint smile.
‘Sicilian Defense: White win rate 52%, Black win rate 27%, draw 21%.’
This book had calculated the number of possible responses by type for each move. After three moves, there were already tens of millions of variations, but the meaningful moves that affected the win rate were limited.
Seoha quietly became absorbed in the book.
Uhyeon glanced to the side and chuckled, as if he had known this would happen.