How difficult can Sudoku become?
A 9x9 Sudoku puzzle has roughly 5.4 billion possible configurations. The space within the grid is finite, but considering the limits of human reasoning, its perceived difficulty can, in effect, approach infinity.
Seha sat in his chair and looked at his team members.
‘Who will be the fastest?’
What was needed to solve this puzzle was not a talent like exceptional mental arithmetic. Which also meant that no one could cross the threshold of this lab with such one-dimensional gifts alone.
‘A chain structure of logic.’
Theo smiled as he solved the puzzle.
One conclusion gave birth to the next, and that in turn became a new constraint, compressing the entire structure. A cyclic structure in which one established a hypothesis, collapsed it, and extracted logic from the ruins.
It was exactly the kind of problem Seha would like. He possessed more innate talent than anyone, but he did not think highly of those who relied on that alone.
‘Here.’
Paradoxically, he focused on the place with the fewest hints. Having few hints also meant that the constraints on the numbers that could enter that position were that much stronger.
Theo began analyzing the topological balance of the eighty-one-cell grid, severing the invisible chains of logic one by one.
‘No way!’
Ben’s pupils shook as if an earthquake had struck them.
A 9x9 grid, a mere eighty-one cells.
But every time one number was entered, the branches of possibility spread out exponentially.
‘Damn it, there’s only one solution.’
Seha had casually created an extremely difficult logic puzzle on the spot. Ordinary Sudoku puzzles were based on elimination, erasing wrong answers one by one.
But the problem Seha had presented had eighty-one numbers organically intertwined, forming one enormous equation.
‘I have to see the whole thing at once.’
Ben realized it intuitively. This was a test asking whether the human brain could be used like a parallel processor. If so, then what about Seha, the one who had created it?
During that brief moment when he wrote down the numbers, just how many possibilities had he been considering simultaneously?
‘I can do it. I’m a genius.’
Grind.
Ben clenched his molars hard.
His brain cells screamed. Thousands of numbers danced inside his head. But once he set a direction, a faint path finally seemed to come into view.
Scratch.
‘Huh?’
The sound of a pencil broke his concentration.
Already?
Was he bluffing?
Scratch, scratch.
Ben glanced sideways. It was Theo. He was filling in the blanks with terrifying momentum.
‘How?’
Ben’s breathing grew ragged. As his mind grew impatient, the clue he had glimpsed tangled itself up. He had to verify everything from the beginning again. But would there be time?
Scratch.
This time it came from the other side.
Cecilia, who had been chewing on a doughnut, moved her pen with elegant motions. And a moment later, Sujeong and Seuri as well.
Not once in his life had he ever felt that he was slow.
‘Am I the only one who hasn’t even started?’
Ben could not believe the situation he was in. When he looked back at the blackboard, the numbers seemed distorted. It was as if a monster with seventeen eyes were laughing at him.
“I’m done!”
Tap!
Theo set his pencil down on the desk. Ben doubted his own ears.
[12 minutes 43 seconds]
A short while later, Cecilia rolled her neck as if it were stiff and spoke in a languid voice.
“Me too.”
[14 minutes 21 seconds]
“Ugh. Third place.”
Sujeong frowned as if displeased.
[15 minutes 10 seconds]
“Ah, I’m last! This is why I didn’t want to do it.”
Seuri clutched his head, then filled in the final number.
[16 minutes 12 seconds]
Ben’s eyes wandered out of focus.
He had not filled in even a single cell. As if his brain had burned out from overload, he could not think at all.
“Doctor?”
Theo called out to Ben, who was sitting there blankly. Startled, Ben lifted his head.
The gazes of five people fixed on him at once. A feeling of helplessness he had never experienced even once in his life. Ben felt unbearable shame.
“I... I...”
What was he supposed to say?
He wanted to make an excuse, but the blank answer sheet lying before his eyes choked off his voice.
‘Was I perhaps nothing more than a frog in a well?’
The thought flashed through Ben’s mind that perhaps his genius had only ever been valid within a very shallow range.
While he had been playing with his feet in a stream, they had been swimming through the deep, deep abyss.
Once a negative thought took hold, all of his brilliant memories of the past began to feel shabby.
“Doctor Simmons?”
Seha called him.
With great effort, he opened his reluctant mouth and answered.
“...Ben.”
“Yes?”
“Please call me Ben. Without the Doctor.”
He was embarrassed.
He remembered his seniors during his master’s program, who had flaunted their degrees more than their ability. Ben had deliberately made equations complicated, then leisurely enjoyed watching them flounder.
‘I get it. Your degrees are the only thing you have to brag about in front of me.’
When the very standard by which he had mocked others came back to him in full, his face burned.
He felt so ashamed he wanted to evaporate and disappear on the spot.
“You couldn’t fill in a single number, Ben.”
“...Yes. I don’t think I deserve to be here.”
Ben lowered his head with a crestfallen expression.
“No, not at all.”
Seha smiled lightly and shook his head.
Ben could not find even the slightest trace of mockery or contempt on his face.
“You couldn’t write down the answer precisely because you are exceptionally outstanding.”
Ben looked up at Seha with a puzzled expression. For words of comfort, his tone was far too plain, as if he were merely stating a fact.
“You probably foresaw many of the possibilities unfolding across the eighty-one-cell grid. Including the entire process of how they collided with one another, contradicted one another, and collapsed.
You must have known that this puzzle had only one solution, Ben. Not finding it does not make you untalented.”
“B-but everyone solved it except me.”
“That’s because we know Seha well.”
Sujeong added in a prim tone.
“Ah, that’s true too. I assumed there would definitely be a higher-dimensional trap. Seha really hates random substitution where luck plays a role.
I suppose we have no choice but to admit that we had an advantage from the start.”
“R-right! You don’t need to be so upset. If I were in Ben’s position, I think I would’ve been the same.”
“Hmm, I think I would’ve done well from the beginning.”
Cecilia said as she put the remaining doughnut into her mouth all at once.
One should not expect tact from her. Theo shook his head and wrapped up the situation.
“Still, a promise is a promise! You can make up for the disappointment next quarter, right?”
Heave-ho!
Theo pulled a large box out from under the desk.
When they opened it, it was a sight to behold. From crumpled receipts from local cafés to invoices sent by advanced companies in Europe and Korea,
there was even a handwritten receipt with crooked letters saying “tteokbokki and gimbap.” Some were stained with black tea and coffee, their letters blurred.
Rustle, rustle.
“What the hell is this now?”
Official letters from the federal government and the National Science Foundation, security clearance renewal requests, unidentified manuals, various bills and notices, and even visa-related documents that some insane researcher must have shoved in were all inside.
“P-please take good care of it.”
Seha looked inside the box, turned pale, and backed away.
At the same time, Sujeong and Cecilia averted their gazes with guilty expressions. Theo beamed and patted Ben on the shoulder.
“Hoo!”
Ben took a deep breath.
This was better, if anything.
There was no better opportunity to grasp the lab’s situation. If he traced the flow of money and paperwork, he would be able to see the destination this lab was aiming for. With a solemn expression, Ben took the box.
“Very well. I’ll give it a try!”
He unbuttoned his shirt cuffs and rolled up his sleeves. Then, at the seat he had been shown, he began digging through the box seriously.
But that lasted only a moment.
The instant he saw a NASA proposal thoroughly stained with tteokbokki sauce, his reason snapped.
***
Before Ben joined, Apex Lab was a complete mess.
Considering the average level of intelligence of the people here, it was truly lamentable.
Whirr—
But now that chaos was being put in order.
The sound of the scanner rang out rhythmically. As if a skilled surgeon were cutting away an affected area with a sharp scalpel, magic unfolded in his hands.
The first thing dealt with was financial opacity.
Countless items were sorted under the “welfare benefits” folder. Receipts fed into the scanner found their rightful places within the system he had built himself.
“Wow!”
Seha let out an exclamation.
The lab’s expenditure details were displayed clearly in pie charts and line graphs.
He analyzed proposals from important institutions and organized them all in one place. The complicated federal security renewal documents and visa-related tasks were integrated into the scheduler he had made, showing their progress in bar form.
“Hm?”
The scheduler flashed red.
Only then did Seuri realize that his visa was on the verge of expiring.
“Ben! We’re out of markers!”
Sujeong, who had been organizing equations on the board, said with a tearful face.
Ben answered without even lifting his head.
“Third drawer on the right in the supply room, next to the blue file. Looking at the history, you’ve been ordering them once every two months.
And only after the stock ran out. I calculated the threshold based on consumption and set up an automatic ordering macro.”
Click.
Theo clicked on the shared folder.
“Oh my God!”
The equations they had been taking pictures of all this time were organized.
LaTeX code, theorem numbers. Everything was placed inside a paper-format layout, to the point that there was almost nothing left to touch.
Theo could not hide his emotion.
Tap-tap-tap-tap-tap-tap.
Having finished the miscellaneous tasks, Ben looked through the research logs with a satisfied expression.
He had loudly declared that he would not attend meetings, but the theories being discussed here were not at that level. Each and every one was a hypothesis that could serve as the subject of a major paper.
The people here were dismantling the Riemann hypothesis almost at the molecular level.
“What is it?”
Ben asked, frowning.
For the past several minutes, Cecilia had been loitering around him. Her gaze was like that of someone looking at a commendable retainer. It made him feel strangely displeased.
“Mm-hmm!”
Cecilia nodded repeatedly, then gave him a thumbs-up and moved away.
Ben heard her mutter faintly.
“...So there was a reason parties always had a porter.”
He shook his head.
The more he tried to understand, the more he lost.
Extremely outstanding, yet lacking something somewhere. Ben decided to accept that fact.
***
The cafeteria on the first floor of the research institute.
Ben sat in a corner seat with a cup of coffee. He had worked so frantically that a week had passed in the blink of an eye. It was a honey-sweet rest after processing thousands of documents.
“How refreshing.”
Seha possessed superhuman intelligence.
But in some ways, he was also an incredibly absentminded human being. Ben felt proud that he could fill in what Seha lacked.
Even miscellaneous work was not bad. In that it transformed chaos into perfect order, this feeling might resemble the pleasure of solving a mathematical problem.
‘Don’t tell me this work suits me?’
It was a feeling different from solving complicated equations—exceedingly primal, yet thrilling.
He shook his head roughly and dismissed the thought.
“Do I have to explain it again? You’re not an idiot, so why can’t you understand this?”
“Seriously! I skipped one class and now I’m losing my mind.”
Words that could not be ignored drifted over from the next table.
Slide.
Ben rose from his seat and approached them. Then he spoke in a solemn voice.
“Students, listen carefully. Even if someone’s intelligence is a little low, or they’re slow in a particular field, that does not make them worthless.
So don’t use bad words like low-intelligence or idiot.”
The students, who had only been half joking, nodded with bewildered expressions.
“I’m glad you understand.”
He smiled with the utmost satisfaction.