My IQ has been increasing year by year.

July 1st.

Chen Zhuo walked out of the administration building.

Five o'clock in the afternoon.

He walked back along the main road.

The camphor trees on both sides of the road form a continuous line, blocking the direct sunlight.

I pushed open the dormitory door, but no one was there.

Chen Zhuo walked to his desk.

He picked up a towel from the table and walked to the sink.

Turn on the tap.

The water pipes had been in the sun all day, so the water that came out was warm.

Chen Zhuo waited for a while, and the water slowly cooled down.

He washed his face and dried it with a towel.

He turned around and went back to his dorm room, glancing at the alarm clock on the table.

5:20.

Chen Zhuo draped a towel over the back of the chair, took out his keys and phone, put them in his pocket, and pushed open the door to leave the dormitory.

Go downstairs.

On the blackboard in the lobby on the first floor, the timetables for several buses leaving the school were written in chalk.

The dormitory supervisor sat in the duty room, fanning herself with a palm leaf fan and watching a small television.

Chen Zhuo walked out of the dormitory building and headed towards the north gate.

I encountered many students on the road carrying woven bags and suitcases.

Some people were smoking by the roadside, while others were walking out of the school in groups of three or five.

As you walk towards the north gate, the railings of the security booth are raised.

Chen Zhuo walked out.

Many stalls have already been set up on both sides of the street outside the North Gate.

There were vendors selling cold noodles, fried rice, and someone had even laid out a cloth on the ground to sell old books and cassette tapes.

Chen Zhuo crossed the road.

The old-established Anhui cuisine restaurant's signboard was somewhat faded, and the wooden door was wide open, with a heavy, transparent plastic curtain hanging at the entrance to block the cold air from inside. Chen Zhuo lifted the curtain and went inside.

A blast of cold air hit me in the face, dispelling the heat from my body.

The shop is small, with seven or eight square tables. It's still early, and only two tables are occupied.

Chen Zhuo glanced at it.

Su Wei sat in a corner by the window.

She had her head down, holding a chopstick in her hand, and was unconsciously fiddling with an empty teacup in front of her.

Chen Zhuo walked over.

Pull out the chair opposite and sit down.

Su Wei raised her head.

"They're here."

She loosened her grip on the chopsticks.

"Um."

Chen Zhuo responded.

I didn't look at the menu.

Over the course of those thirty days, they tried almost every dish on the menu of several restaurants in the vicinity.

"Boss."

Chen Zhuo turned his head and shouted at the cabinet.

The boss was a middle-aged, overweight man with a white towel draped around his neck, who walked over with a small notebook in his hand.

"What should we eat today? The usual three dishes?"

The boss asked with a smile.

Chen Zhuo nodded.

"Braised stinky mandarin fish, Wenzheng Mountain bamboo shoots, stir-fried water spinach, and a vegetable and tofu soup."

"What about the staple food?"

"Two bowls of rice."

"Okay, coming right away."

The boss made two notes in his notebook, then turned and went to the kitchen.

Su Wei picked up a bowl from the table.

She picked up a stainless steel kettle from the side and poured some boiling water into their bowls and chopsticks.

Water vapor is rising up.

She skillfully used her chopsticks to hold the bowl and swirl it around twice, then poured water into the bowl and pushed the scalded bowl and chopsticks towards Chen Zhuo.

After completing the set of movements, she picked up the kettle again and poured two cups of barley tea.

"Have you finished packing?"

Su Wei put down the kettle and picked up the teacup.

"Just one bag."

Chen Zhuo took the teacup.

"The large item will be mailed through the post office in a couple of days."

"When are you leaving?"

"Number Seven".

Su Wei nodded and blew on the steam rising from the cup.

My flight is at 7 a.m. tomorrow.

"That means you have to get up very early."

Su Wei took a sip of tea.

"I'll catch up on sleep once I'm on the plane."

The two said nothing more.

The barley tea on the table smelled of burnt barley.

The curtain at the back of the kitchen was lifted, and a waiter came over carrying a tray.

The braised stinky mandarin fish was placed in the very center of the table.

Next up are the bamboo shoots from Wenzheng Mountain, cut into long strips and stir-fried with a few slices of cured pork, glistening with oil.

The water spinach was stir-fried until it was very green, and it was served with minced garlic.

Finally, there were two bowls of tightly packed white rice.

"The dishes are all ready, please enjoy."

The waiter put down the plate and left.

Chen Zhuo picked up his chopsticks.

He picked up a piece of meat from the belly of the fish, removed the row of fine bones from the side, and put it in the bowl.

"I've eaten the most fish from this restaurant this month."

Su Wei also picked up a piece of fish.

"The meat is firm, and the broth is well-seasoned."

Chen Zhuo took a bite of rice.

"Once you get to Lujiazui, it will be very difficult to find this kind of taste."

Su Wei chewed slowly.

"The food over there seems to be on the sweeter side."

"It's nice to have something sweet every now and then," Chen Zhuo said.

"It gets boring if you eat too much."

Su Wei spat a fish bone into the waste dish on the table.

Outside the window, the sky began to darken.

One by one, the streetlights lit up.

"What position did Teacher Shen assign you?"

Chen Zhuo picked up a piece of bamboo shoot with his chopsticks.

"Quantitative Strategy Group, Research Intern."

Su Wei took a bite of rice.

"No need to go to the branch office counter, go directly to the core data center to organize historical K-line data and run backtesting models."

"Is the computing power sufficient?"

"The brokerage firm's servers are much stronger than the school's."

Su Wei looked at the plate in front of her.

"They have a dedicated line that connects directly to the exchange, with latency in the millisecond range."

Chen Zhuo nodded.

"Not bad, that's good."

Chen Zhuo took a sip of tea.

"Um."

Su Wei nodded.

"I've looked at some of the test data they sent. There's too much irrational volatility in the market. Those traders who came back from Wall Street like to apply a seemingly rigorous continuous calculus formula to the market." Su Wei put down her chopsticks.

"But the market is actually discrete; every transaction, every buy order and sell order, is an isolated node."

Chen Zhuo continued picking up food with his chopsticks.

"The boundary conditions of the continuous model will fail when dealing with extreme market conditions."

Chen Zhuo followed her words.

"Like that 0.5% residual you helped me fix before."

Su Wei looked at him.

"That's just a small patch."

"But in a Ponzi scheme involving hundreds of millions of dollars, a residual of 0.5% can become a very high loss if it is amplified."

Su Wei picked up her chopsticks again.

"If you make a mistake in math on paper, you can erase it with an eraser; but if you make a mistake in the financial markets, you might as well jump off a building."

Chen Zhuo finished the last bite of water spinach.

"Don't put too much pressure on yourself."

Chen Zhuo spoke in a calm tone.

"The model is ultimately written by a person. As long as you don't try to save that last penny, the model won't easily collapse."

Su Wei picked up a slice of cured meat.

"What about Princeton?" she asked.

"Same here."

Chen Zhuo put down his chopsticks and picked up his bowl to ladle out the soup.

"The old man is stubborn. He wouldn't let me stay at the international students' residence and insisted that I stay at his house."

"Living at your advisor's house?"

"Um."

"Does it include meals?"

Su Wei made a rare joke.

"I heard that your wife has been learning to cook recently."

Chen Zhuo placed a bowl of vegetable and tofu soup next to Su Wei, and then served himself a bowl.

"Then they shouldn't starve to death."

"We won't freeze or starve; we're just going to study."

Chen Zhuo picked up the bowl and took a sip of soup.

The light flavor perfectly balanced the saltiness of the stinky mandarin fish.

We've almost finished eating.

The three dishes on the table were almost empty.

The store started to get busier, with voices and clinking glasses blending together.

Chen Zhuo took a tissue and wiped his mouth.

He crumpled the tissue into a ball and threw it into the trash can.

Without any pause, Chen Zhuo placed his hands on the table and stood up.

Su Wei held the last half cup of tea, looked at him, neither stopping him nor reaching for her wallet.

As per the previously agreed-upon rule, he would pay for the last meal.

Chen Zhuo walked to the counter.

"Boss, check please."

The boss walked over with a calculator and glanced at table number six.

"Braised stinky mandarin fish, 38 yuan; bamboo shoots, 18 yuan; water spinach, 8 yuan; rice, 2 yuan; the soup is free."

The boss pressed a few keys on the calculator.

"Sixty-six in total, give me sixty-five."

Chen Zhuo pulled out two hundred-yuan bills from his pocket; they were part of the bonus that Vice Principal Zhou had arranged for him to receive.

He pulled out a bill and handed it to the shopkeeper.

The shopkeeper took the money, shone it under the overhead light to check the security thread, then opened a drawer and took out a twenty-yuan note, a ten-yuan note, and a five-yuan note. "Keep this safe, and have a good trip."

Chen Zhuo took the change and put it in his pocket.

He turned around and walked back to his seat.

Su Wei had finished her tea.

"Have the school's bonuses been distributed yet?"

Su Wei watched him pull out a chair and sit down.

"It's been sent."

"It's a bit more than I expected; enough to pay for this meal."

Chen Zhuo had just settled into his seat.

My gaze fell on the table.

Next to where he used to put his teacup, a long, black box had appeared out of nowhere.

There was no wrapping paper, no ribbons.

It's a very high-quality black pencil case.

A small white six-pointed star is printed on the box lid.

The Montblanc logo.

Chen Zhuo glanced at the box but didn't reach for it.

He raised his head and looked at Su Wei across from him.

Su Wei placed her hands flat on the edge of the table and leaned back slightly.

Her expression was indifferent.

Su Wei looked at Chen Zhuo.

Consider this payment for the consultation fee you charged me for fixing that 0.5% residual formula.

Chen Zhuo looked at her without saying a word.

Montblanc Meisterstück 149.

Su Wei raised her chin slightly and pointed to the black box.

"I know you don't lack money."

Su Wei's tone remained completely calm.

"But I've checked, and the draft paper at the Institute for Advanced Study in Princeton is quite thick and has a somewhat rough surface."

"When you're writing matrix derivations over there, ballpoint pens tend to run out of ink, and regular fountain pens tend to scratch the paper."

"This pen has a thick nib and the ink flows smoothly. If we switch to a better tool, we can solve problems faster."

The words fell.

The noise outside the restaurant seemed to be shut out.

Chen Zhuo looked at the black box on the table.

Chen Zhuo extended his hand.

He didn't open the box to look at the gold pen inside.

Instead, he picked up the black box very naturally and put it in his pocket.

Chen Zhuo leaned back in his chair.

He looked at Su Wei, a faint smile appearing in his gentle eyes.

"I'll take the pen."

Chen Zhuo's voice wasn't loud, just enough for Su Wei to hear clearly.

"but."

He paused.

"I heard that the water flow in Class 149 is very strong, and it takes a lot of ink to write on it."

Chen Zhuo looked into Su Wei's eyes.

"Once I arrive in Country W, if I run out of supplies, can I take the receipts to General Manager Su in Lujiazui and apply for reimbursement?"

Su Wei looked at him.

She didn't laugh, nor did she find the joke boring.

She stood up decisively.

He casually picked up the shoulder bag draped over the back of the chair and slung it over his shoulder.

He looked down at Chen Zhuo and uttered a single word.

"OK."

After saying that, she turned around.

"Let's go."

Chen Zhuo stood up and pushed back his chair.

The two walked out one after the other, passing through the lobby.

I lifted the heavy plastic curtain and stepped onto the street.

The heat was slightly less at night than during the day, but the wind was still warm on the skin.

The streetlights cast a dim, yellowish light, making people's shadows appear long.

They crossed the road and entered the north gate of the University of Science and Technology of China.

Walking on the main road on campus.

They walked side by side, just like every night before.

There was always a safe distance of about one meter between them.

No one took the initiative to approach, nor did they deliberately distance themselves.

I passed by the playground, the second canteen, and the teaching building.

No one speaks.

We walked until we reached a fork in the road below the girls' dormitory.

To the left is Su Wei's dormitory building.

To the right is Chen Zhuo's dormitory building.

Su Wei stopped in her tracks.

Chen Zhuo also stopped and stood a meter away from her.

The streetlights shone down from overhead.

Girls carrying water bottles or plastic basins walked past them, coming and going.

Su Wei turned her head and looked at a paving stone under the street lamp.

Her tone was no different from when she was discussing math problems in the library.

There were no ups and downs, no waves.

"My flight is at 7 a.m. tomorrow, so I'm skipping dinner."

She didn't say goodbye, nor did she say we should keep in touch.

This statement, "I'm not eating anymore," officially ended their month-long meal-sharing agreement.

Chen Zhuo stood to her side.

With his hands in his pockets, his right fingers gently touched the sturdy black pencil case through the fabric.

He nodded slightly.

Have a safe journey.

Su Wei raised her head.

I glanced at him.

His eyes looked bright and calm under the streetlights.

She nodded.

"The same to you."

Done.

Su Wei did not linger.

She turned around, started walking, and headed towards the gate of the girls' dormitory building.

They didn't stop for even a moment.

Chen Zhuo stood there, watching her back as she walked up the stairs, pushed open the glass door, and disappeared into the shadows around the corner of the corridor.

I turned away, turned around, and walked along the main road toward the boys' dormitory building.