Translator: Dreamscribe
Seo-ha’s gaze wavered.
Dozens of eyes looking at him.
Everyone was waiting for Seo-ha to open his mouth.
It was the first time in his life he had ever received attention in front of so many people.
‘I... I need to answer first. According to the method the professor proved....’
It was only the first day.
Seo-ha wanted to be respectful.
So he decided to honor the professor’s method.
Seo-ha quickly scanned the blackboard with his eyes.
A massive blackboard made up of four joined together. An enormous amount of formulas was densely written on it.
‘Diophantine equation.’
It was a field Seo-ha liked.
In the 3rd century, the Alexandrian mathematician Diophantus systematically dealt with various equations with integer solutions in his book Arithmetica.
This formula, which had been forgotten for a time after the burning of Alexandria, was revived by modern mathematicians such as Fermat, Euler, and Gauss.
Seo-ha’s eyes began to read the formulas at an incredible speed.
Starting from the definition at the top left of the first blackboard.
His brain responded instantly. He applied the basic form of the linear Diophantine equation using the Bézout identity.
Extended Euclidean algorithm.
His brain reconstructed the algorithm in an instant. He simulated the reverse calculation process all at once.
Second blackboard.
More complex forms appeared.
Integers expressed as the sum of two squares. Fermat’s theorem on sums of two squares unfolded in his head.
His gaze moved further down.
Fermat’s Last Theorem and Euler’s method of infinite descent were instantly applied in his mind, and he began verifying the formulas.
He could see the expanded expressions used by Professor Park.
Applying Jacobi’s triple product identity...
It had only taken a few seconds to get to this point.
‘Huh?’
The formula that had been flowing smoothly, as if reading without interruption, suddenly hit a wall.
Seo-ha’s eyes stopped.
Something was wrong.
Near the top of the third blackboard, in the middle of a complex expansion.
The sign was wrong.
It should be a minus, not a plus.
In Euler’s partition function expansion using the pentagonal number theorem, the sign must be changed for the formula to hold.
Thump.
As Seo-ha stared at the blackboard, the professor waited for a moment to give him time.
Yu Seo-ha was the only perfect scorer on the second exam. Although he was young, there was confidence that he could keep up to this level.
“All right! Yu Seo-ha, why don’t you come up and explain?”
'Is he too nervous? It would be a big problem if he has stage fright....'
Professor Park had seen such cases many times.
Presentation was not optional for a mathematician, but a necessity.
He thought he needed to help the student gain experience.
Thump.
Seo-ha’s heart pounded violently.
There was pressure to stand in front of people. But more than that, the error in the blackboard writing persistently tormented him.
Since there didn’t seem to be any problems in the formulas that followed, it was likely just a simple notation mistake by the professor. And that made it even more bothersome.
‘Is it okay to point this out?’
Seo-ha’s parents had been afraid that their excessively exceptional son might grow up to become a flawed person. So they had emphasized, perhaps too much, courtesy, consideration, and respect for others.
With little experience, Seo-ha couldn’t tell whether it was acceptable for a student to correct a professor’s formula.
And the symptoms he had been suppressing well until now exploded violently under the complex influence of all these factors.
Thump, thump.
“...Yes.”
Seo-ha stood up from his seat.
His legs trembled.
Even while trying to figure out how to present, the incorrect sign on the third blackboard kept flickering in his mind like a broken neon sign.
‘It should be a minus.’
He moved step by step toward the podium.
But the more he walked, the more his breathing grew labored.
‘I want to correct the formula.’
His fingers moved unconsciously.
His right index finger kept mimicking the motion of changing a plus to a minus in the air.
His chest felt tight, and cold sweat trickled down his back.
Once he stepped onto the podium, he could see even more students’ faces.
Expectation, curiosity, concern, ridicule, pity.
Various emotions appeared and disappeared on their faces.
“All right, shall we begin?”
Professor Park handed over the chalk with an encouraging smile.
Seo-ha took it with trembling hands.
Blink.
Blink.
The sign still blinked.
“The basic approach to Diophantine equations is....”
He began to speak.
He tried to start explaining while looking at the first blackboard, but his eyes kept being drawn to the error.
Wee-woo wee-woo-
It even felt like he was hearing hallucinations now.
He couldn’t take it anymore.
His face had turned pale.
The students sensed something was wrong with Seo-ha.
“What’s wrong with him?”
“Is he sick or something?”
“Poor guy. He must be really nervous.”
Whispers rose from here and there.
The professor shook his head.
Thinking it might be too much for today and intending to send him back with the hope of another chance, at that moment, Seo-ha moved.
Step, step.
Seo-ha, who had looked like he was in a panic, suddenly raised his head and, without hesitation, walked toward the third blackboard. Then he went up on tiptoe and tried to correct the blackboard.
But it seemed too high for him; he couldn’t reach it.
It was a somewhat ridiculous scene.
But no one could laugh at this bizarre sight.
“Student Yu Seo-ha, what are you trying to do right now?”
The professor cautiously asked.
“The sign... I have to fix the sign.”
Professor Park furrowed his brow.
Then he stared at the third blackboard for a while.
Finding a single symbol error among such a tangled mess of formulas was never easy.
But since Seo-ha was trying to erase something, he could quickly pinpoint it.
“Ah....”
A sigh escaped from Professor Park’s mouth.
An expression of embarrassment crossed his face.
The sign was indeed wrong.
“Seo-ha is right.”
Professor Park murmured as he gently rubbed the sign with his finger and corrected it, from plus to minus.
Seo-ha’s movement stopped.
The neon sign turned off.
Phewww-
Seo-ha let out a long sigh of relief.
The suffocating pressure that had been weighing on his chest disappeared, and his breathing returned to normal.
Seo-ha smiled brightly.
Seeing that, Professor Park felt an indescribable emotion rise in him.
“Thank you, Yu Seo-ha. That was an incredibly sharp observation.”
Professors, being human, sometimes made mistakes in signs or numbers when writing formulas while thinking about something else.
Seo-ha gave a polite bow.
Professor Park was a scholar with much experience. And he knew well that among great mathematicians in history, there had always been eccentric geniuses.
The lecture room was quiet.
The students were silently astonished.
Professor Park turned to face the students. And immediately, his expression hardened.
“You all took notes diligently, but none of you spotted the error. Were you just copying mindlessly without thinking?”
A look of disappointment flashed across Professor Park’s face.
He had expected more from gifted students selected from across the country.
Ji-hoon clenched his fists tightly.
His pride was wounded.
Ko Chang-seok adjusted his glasses and flipped through his notebook.
Embarrassment was evident on his face.
Su-jeong quietly accepted the situation as if it were only natural.
“And Seo-ha.”
“Yes.”
“You hesitated earlier, didn’t you? This kind of thing is always okay to point out.
On the surface, we may appear to be teacher and student, but on a deeper level, we are companions walking the vast path of mathematics together. Without exchanging thoughts with one another, mathematics cannot progress.
Rather, when you have doubts, regardless of age or status, you must speak up. Understood?”
“Yes! Professor.”
Seo-ha nodded repeatedly with joy.
Professor Park looked at him with satisfaction.
Seo-ha returned to his seat, and the class resumed.
Freed from the pressure, Seo-ha exchanged opinions with the professor regarding the proof. Seo-ha came to understand why Professor Park had used such an approach.
“For high school students, Analytic Number Theory is still a bit too early.”
Though unintentional, this remark from Professor Park provoked the students.
Everyone began focusing on the lecture as if unwilling to be left behind. Energy returned to the lecture hall. Professor Park found this atmosphere highly satisfying.
But the students’ thoughts were different.
‘So Yu Seo-ha can do it, and we can’t?’
‘I’ve studied advanced number theory. He just explained it simply because he thought we wouldn’t understand?’
No one had ever treated them this way in their entire lives.
“Ji-hoon, you understand this theorem, but the others don’t. So let’s not get too far ahead.”
Words they had always heard.
No matter where they went, they had always been special, yet here, they were the ones who needed to be considered.
The students were feeling humiliated.
Stimulated by Seo-ha, Ji-hoon suddenly stood up.
“I heard there's a way to solve Diophantine equations using continued fractions?”
Not to be outdone, Ko Chang-seok jumped in.
“Finding Pythagorean triples is also a Diophantine equation, right? Is there a general formula?”
The flames of competition burned in the students’ eyes. Each of them tried to ask deeper and sharper questions like Seo-ha to make an impression.
Professor Park enthusiastically answered, moving back and forth across the board with a broad grin.
On the very first day, Seo-ha had poured the catalyst called competitiveness into the top gifted students in the nation, awakening the potential that had lain dormant within them.
But Su-jeong knew Seo-ha better than anyone else in that room.
'No matter how much you guys try....'
Su-jeong scoffed.
She was determined to stick to her second-place strategy.
‘How are you supposed to beat that?’
Even what Seo-ha had shown today wasn’t his true self. She couldn’t even tell where the bottom of his abilities lay, let alone his real level.
Time passed, and it was nearing the end of the lecture.
Professor Park checked the time and smiled.
“Today was our first class, but it was very lively. I can feel your passion.”
The students nodded, looking relieved.
“If we just end now, it’ll be boring, so I’ll make a fun suggestion before we finish.”
Professor Park erased the blackboard clean and wrote a new problem.
[Find the maximum product of natural numbers whose sum is 2077.]
“I’ll give a privilege to the students who solve this quickly.”
Everyone stared at the problem with tense expressions.
In the Winter School, even the smallest privilege was directly tied to selection, so it had to be seized without fail.
“I’ll give the first half of the solvers the right to choose their own roommates.”
Murmur.
The students’ eyes widened.
Choosing a roommate with whom they would live for two weeks was a very important matter.
There was no rest here.
Everyone would study even in the dorms. They all knew well that the most important factor affecting the study environment was the roommate.
Snoring was the least of their concerns.
If someone smelled because they didn’t shower daily or had a habit of muttering to themselves, it would be a serious problem.
The students began subtly glancing around.
Ji-hoon’s gaze settled on one student. He was biting his nails and had placed them on the desk.
‘Ugh! Definitely need to avoid that one.’
Everyone was thinking the same, trying to decide silently whom they should pick.
But they weren’t seasoned third-years in high school.
They immediately buried their heads in their notebooks and began solving the problem intensely.
'Oh no!'
Ji-hoon and Su-jeong also began looking at the problem.
“All right then, shall we begin?”
The professor looked around at the students.
The maximum product of natural numbers whose sum is 2077.
It could be trickier than it looked, but with the right approach, it was solvable within thirty minutes.
The students began tackling the problem in their own ways.
But not Yu Seo-ha.
He simply stared blankly, then looked at the professor and gave a signal.
Then he timidly raised his hand and shyly said,
“Um... Professor. I solved it. Can I go ahead and choose a roommate?”
Silence fell.
Even the students who had been maintaining composure through constant effort during class couldn’t help but stop their pens this time.