My IQ has been increasing year by year.

It's only a ten-minute walk from the USTC dormitory building to the food stalls on the back street.

It was already completely dark.

Several huge fans were set up in front of Old Li's barbecue stall, blowing out a whirring sound that filled the air with the mixed aromas of cumin, chili powder, and charcoal-grilled mutton fat. Low folding square tables and red plastic stools were set up along the roadside.

In early June, business on the back street was unusually good.

Looking around, more than half of the tables were pushed together, and all the people sitting there were boys wearing shorts and flip-flops, with a few girls occasionally mixed in. There were empty green beer bottles everywhere underfoot.

Not far from the table that Da Yong and his friends had chosen, seven or eight boys were shirtless, one foot on a plastic stool, loudly drinking and beating each other. The table was a mess of cups and plates, and one boy was slumped over the edge of the table, his shoulders shaking, clearly drunk and crying.

This is the unique atmosphere of graduation season.

Farewell dinners were everywhere.

The air was thick with the pungent smell of alcohol, mixed with the sounds of laughter and tears that seemed ready to erupt at any moment.

Dayong pulled two tables together, plopped down, and shouted towards the oven.

"Old Li! Ten skewers of lamb kidneys, you start! Thirty skewers of beef tendon! Two plates of edamame and peanuts! And two cases of Urumqi beer, one at room temperature and one chilled!" "Alright! Coming right away!"

The boss, his eyes stinging from the smoke, responded loudly while flipping through a large handful of meat skewers.

Chu Ge was forced onto a stool by Da Yong.

He looked around; it was too noisy.

He habitually reached into his pocket, but found he didn't have his phone with him.

The tension was still running high in my head, my mind filled with the progress bar that had only gone five percent.

"Dayong, you've ordered too much. We can't finish it."

"Eat quickly, I need to go back and finish up after I finish. If that module gets stuck, all my hard work these past two days will have been for nothing."

Da Yong ignored him.

The waiter brought over two plates piled high with edamame and peanuts, and casually placed two cases of beer under the table.

Dayong bent down, picked up four bottles of chilled Wusu beer, and placed them on the table with a thud.

He didn't take the bottle opener.

Grab a disposable chopstick, hold it against the edge of the bottle cap, and support it with your thumb.

"Bang!"

"Bang!"

With four consecutive sharp cracks, the bottle cap flew off and smashed into the open ground next to it, white beer foam gushing out from the bottle opening.

Da Yong grabbed a bottle and slammed it down heavily in front of Chu Ge.

Stop thinking about your crappy code.

Da Yong pulled over a plastic stool and sat down, staring into Chu Ge's eyes.

Chu Ge frowned.

"What's gotten into you today? Why did you have to drag me out?"

Da Yong didn't respond. Instead, he reached out, grabbed a edamame, and popped it into his mouth, chewing it once.

"Old Chu."

Da Yong spat out the edamame shells and suddenly spoke.

Do you know what day it is today?

Chu Ge was taken aback.

"Number 14, what's wrong?"

Chu Ge answered casually.

Da Yong picked up the bottle of wine in front of him and slammed it heavily on the table.

June 14th.

Da Yong's voice was loud, drowning out the noise from the next table.

Today, you turn eighteen.

Chu Ge's hand, which had reached out to grab the peanuts, froze in mid-air.

He froze completely.

After several seconds, he slowly withdrew his hand, looked at Dayong, and then at Lu Jia and Chen Zhuo, who were standing silently beside him.

Holy crap.

Chu Ge cursed instinctively.

He really forgot.

"You remember now?"

Da Yong grinned, revealing his gleaming white teeth.

"Starting today, you're not only a legally recognized adult, but also the first real man in both of our dorms to go to an internet cafe all night without using a fake ID." Chu Ge opened his mouth, and the frustration that had been building up because the code hadn't finished running suddenly dissipated like a punctured balloon. He glanced at the cold beer bottle in front of him and suddenly felt his eyes getting hot.

But he immediately rubbed his face vigorously, cursing as he covered it up.

"Depend on."

Chu Ge picked up the wine bottle.

"I thought you had a major hemorrhage today and were really going to treat me to a better meal, but it turns out you were just using this as an excuse to get me drunk."

"It must be administered."

Da Yong raised the bottle.

Lu Jia pushed up his glasses and picked up the wine bottle as well.

Chen Zhuo sat opposite him, a gentle smile on his lips, and picked up the bottle with one hand.

"Let's have one!"

"Da Yong shouted."

Four green glass bottles collided in the middle of the table, making a crisp clinking sound.

The ice-cold beer slid down his throat, and Chu Ge let out a big burp, seemingly relieving some of the fatigue that had been building up for half a month. The boss came over with a large iron plate, piling sizzling, oily grilled kidneys and tendons in the middle of the table.

"Eat it while it's hot!"

Dayong grabbed a string of kidneys, took a bite, and his mouth was full of oil.

He chewed as he reached into his pocket.

"A coming-of-age ceremony shouldn't just involve drinking."

Dayong pulled something out of his pocket and slammed it onto the plastic tabletop with a thud.

The sound was muffled, and the plastic table shook as it was hit, causing the peanuts on the table to jump up.

It was a rectangular metal shell.

It was grayish-black, without any luster, and its surface bore rough lines left by lathe cutting tools. The lines were straight and angular, exuding an extremely brutal industrial feel. Chu Ge was stunned for a moment.

"What is this thing?"

"The lighter casing, windproof."

Da Yong said casually.

"I used scrap titanium-aluminum alloy from the lab to machine it myself, which ruined several of my senior's cutting tools."

Chu Ge picked it up.

Very heavy.

It was heavier than a lighter should be.

The edges have been polished so they won't cut your hand, but they feel extremely hard when you hold them.

"Alloy materials used in aerospace."

Da Yong took a sip of his drink and looked at Chu Ge.

"You're eighteen now, you're a man now. When you enter society and encounter any difficulties, you need to be as tough as this thing. You can use it for self-defense or to crack walnuts. Just remember, no matter what, don't be a coward." Chu Ge held the metal casing.

He looked at Dayong's face, which was covered in cumin, opened his mouth, and finally only uttered a curse.

"Wang Dayong, are you fucking sick? This is so heavy, I find it too cumbersome to carry around."

But instead of putting it down, he stuffed the titanium alloy shell directly into his pants pocket.

"It's my turn."

Lu Jia put down the meat tendon in his hand, carefully wiped the grease from the corner of his mouth with a tissue, and then took out a notebook from his bag. He pushed the notebook in front of Chu Ge.

Chu Ge looked at the familiar notebook, and his eyes twitched slightly.

"Lu Jia, don't tell me that the gift you gave me for my eighteenth birthday was a book of advanced calculus problems."

"It's much more important than that."

Lu Jia pushed up his glasses, his expression as serious as if he were giving an academic presentation.

"According to the laws of human biology, by the age of eighteen, the development of your prefrontal cortex is basically complete, and you are about to enter a period of slow synaptic pruning and decay." Lu Jia turned to the first page of his notebook.

The diagram above shows an extremely complex parabola, surrounded by numerous parameters.

"Based on your recent schedule of spending more than fourteen hours a day in front of a computer screen, and an average of less than 5.5 hours of sleep, I have created a decay model using a Markov chain," Lu Jia said, pointing to a data point at the bottom of the chart.

"Based on calculations, your probability of experiencing early hair loss, receding hairline, and memory decline within three years is 73.4%." Da Yong, who was sitting at the same table, couldn't help but spit out a mouthful of beer onto the ground.

Da Yong coughed and slapped his thigh while laughing wildly.

"Hahaha! Old Chu, he's predicting you'll go bald within three years!"

Chu Ge's face turned completely black.

He looked at Lu Jia's face, which showed no hint of a joke, and said through gritted teeth.

"Lu Jia, it's my birthday today, and you gave me a hair loss prevention probability chart. Do you want me to bury you in Old Li's oven today?" "Honest advice is hard to swallow."

Lu Jia remained completely unmoved.

"Turn to the third page. There you'll find a nutritional intervention plan I've calculated for you, a sleep matrix, and even how you can minimize your alcohol intake at dinner parties by adjusting the angle of your glass and the frequency of toasts."

Lu Jia looked into Chu Ge's eyes.

"At eighteen, you have independent civil rights. I hope you can face science squarely and rationally plan your hair follicles and liver." Chu Ge looked at the densely packed words.

He knew, of course, how inflexible Lu Jia was, but it was precisely because of his inflexibility that...

Chu Ge knew that Lu Jia had probably spent a lot of the time he would normally spend on mathematics just to write these dozens of pages of calculations.

Chu Ge sighed, closed the laptop, and placed it next to the lighter case.

"Okay, thank you. I promise to take good care of my hair."

Chu Ge picked up his glass and clinked it against Lu Jia's.

There was a moment of silence on the table.

Da Yong and Lu Jia turned their heads at the same time to look at Chen Zhuo opposite them.

Chen Zhuo sat on a plastic stool, twirling a half-eaten lamb skewer in his hand.

Seeing them looking over, Chen Zhuo smiled and tossed the skewer into the empty plate on the table.

He took a napkin and slowly wiped his fingers.

Then, Chen Zhuo put his hand into his pocket.

He took out a neatly folded piece of white paper and casually tossed it onto the greasy table in front of Chu Ge.

"I have no money."

Chen Zhuo spoke in a calm tone.

"I didn't go to the workshop, I just wrote it down casually."

Chu Ge looked at the paper, picked it up with some confusion, and slowly unfolded it.

The lighting at the barbecue stall was dim, and the incandescent bulbs overhead were covered with greasy lampshades.

Chu Ge moved a little closer.

At first, he thought Chen Zhuo had written some kind of blessing or IOU on it as a prank.

But when he saw the black writing on the paper...

Chu Ge's eyes narrowed sharply.

His previously relaxed posture vanished instantly; he leaned forward involuntarily, his back lifting off the chair, his neck stretched out, staring intently at the symbols on the paper. Not code.

There is not a single English letter on it, nor any logical structure of any computer language.

It was a set of matrices connected together.

These are several mapping formulas for discrete algebraic groups written by Chen Zhuo in extremely clean handwriting.

As a computer genius who had been coding for several years, Chugo's intuition was terrifying.

He saw the core of this thing at a glance.

He was stuck in his dorm room for half a month, almost causing the server to crash due to a deadlock in the underlying search mechanism.

He has been trying to use computer logic to untangle those tangled threads, layer by layer.

But the mathematical formulas on this paper jumped straight out of the tangled yarn.

It redefines the rules of nodes from a high-dimensional perspective.

Simply translate this formula into code and apply it; all this type of concurrent congestion will automatically disappear in the face of this mathematical principle. This isn't just optimization; for a company, it's practically its most prized possession.

Chu Ge gripped the edge of the paper, which made a slight rustling sound.

He looked up and stared at Chen Zhuo as if he were a monster.

"you."

Chu Ge's voice was somewhat hoarse.

"When did you understand database architecture?"

Chen Zhuo picked up the plastic cup and took a sip of room-temperature Wusu beer.

"don't know."

Chen Zhuo put down his cup.

"I'm not even very good at pressing Enter to start a newline."

"So what are you doing...?"

"When I passed by your screen, I saw you scratching your head because of a few data points stuck together, which was a bit of an eyesore."

Chen Zhuo took a skewer of grilled meat and took a bite.

"While reading in the library, I casually calculated your nodes as a topological space."

Chen Zhuo looked at Chu Ge with a nonchalant air and a touch of genius-level cunning in his eyes.

"The underlying logic is here; go back and translate it into code yourself."

Chen Zhuo smiled.

"This is an adult red envelope. You'll use it to get freelance work in the future. Remember to treat people to meals. If you still can't make a living with this, I suggest you switch to learning something else as soon as possible." Chu Ge stared at Chen Zhuo for several seconds.

He didn't say thank you.

For people like them, the weight of this piece of paper cannot be borne by a simple thank you.

If this thing were given to one of today's internet startups, it could fetch a price that would leave ordinary people speechless.

Chu Ge carefully refolded the paper along the original creases, even pressing the creases flat with his fingers.

He put the piece of paper in his pocket and patted it.

"It's impossible to change majors."

Chugo picked up the beer bottle again, his eyes flashing with an alarming light.

"This toast is to mathematics."

He tilted his head back and gulped down half the bottle.

Late at night.

Old Li's barbecue stall business is booming.

The senior students at the next table were already quite drunk.

Bottles were scattered all over the floor.

A boy took off his shirt, stood on a chair, held up a half-empty bottle of beer, and cried and shouted.

"Brothers! We've graduated! Don't fucking forget each other!"

The other boys huddled together and started singing off-key old songs at the top of their lungs.

The sound was so loud that people at several nearby tables turned to look.

Dayong had also drunk quite a bit.

His face was flushed, and his forehead was covered in sweat.

He turned his head and looked at the group of senior students who were crying their eyes out, making choking noises.

"Old Chu, look at those bastards."

Da Yong, slurring his words, reached out and wrapped his arm tightly around Chu Ge's shoulder.

"You cry like this after drinking a little horse piss, you're pathetic."

Da Yong raised the bottle in his hand and slammed it against the empty bottle in front of Chu Ge.

A loud thud.

"We're happy to celebrate your coming of age today!"

Da Yong, reeking of alcohol, shouted loudly.

"We won't follow their example! Our hard times are yet to come!"

Da Yong patted his chest and pointed to the USTC gate in the distance.

"Junior year is nothing! Next year we'll be seniors, the year after that we'll be first-year graduate students, then second-year and third-year graduate students. We brothers will be able to walk all over USTC for another two years! When we graduate, I'm going to take over Old Li's business!" It was very noisy around.

But then, for a moment, the table fell silent.

Da Yong was still grinning foolishly, while Lu Jia was wiping the beer stains that had splashed on the table with a tissue.

Chu Ge sat in Da Yong's arms.

His hand was reaching for the meat skewers on the table.

Hearing Dayong say that he'll be a senior next year and a first-year graduate student the year after, I felt a surge of

Chu Ge's hand paused very slightly in mid-air.

The movements were very small.

But Chen Zhuo, who was opposite him, could see it very clearly.

Chu Ge's gaze didn't fall on the skewer of grilled meat; he stared at the senior students at the next table who were burying their heads in their hands and crying for a long time.

A gust of wind blew by, and the white smoke from the barbecue grill drifted over and enveloped their table.

The smoke was so thick that it made it impossible for people to open their eyes.

Chu Ge felt a sudden stinging sensation in his eyes, and his eye sockets quickly turned red.

He didn't raise his hand to rub his eyes.

He suddenly turned his head, broke free from Da Yong's arm, and grabbed a newly opened bottle of Wusu beer from the table.

He held the beer bottle cap in his teeth.

With a sharp crack.

The bottle cap flew off.

Chu Ge didn't even pick up the cup; he simply raised the sizzling Urumqi beer and stood up.

"Shut the fuck up!"

Chu Ge's voice was loud, even a little hoarse and cracked than usual.

"Today I'm an adult! Anyone who doesn't get drunk is a coward!"

He raised the bottle into the air.

"Damn! No matter where we are in the future, we'll always be awesome!"

After saying that, Chu Ge tilted his head back.

His Adam's apple bobbed violently as he forced down half a bottle of beer like water.

Wine dripped down his chin and onto his wrinkled T-shirt.

Da Yong laughed heartily, grabbed the wine bottle, and stood up.

"Always awesome! Let's go!"

Lu Jia also stood up and picked up her cup.

Chen Zhuo sat opposite him, then stood up, holding a disposable transparent plastic cup half-filled with beer.

He looked at Chu Ge.

Looking at Chu Ge's red eyes and his arm with bulging veins from gripping the bottle so tightly, I could see...

Then, Chen Zhuo looked up.

Drink the wine in the glass in one gulp.

The light overhead flickered.

Summer nights are still long.