I was a top student in America.

Li Ao pushed open the glass door of the examination center building, and the cold wind that hit him made him squint.

The candidates below the steps hadn't completely dispersed yet; they gathered in twos and threes, sighing and lamenting over their answers on their draft papers.

He hoisted his backpack onto his shoulder, and just as he stepped down the stairs, he suddenly stopped—a familiar figure was standing under the trees on the outer edge of the crowd.

Liu Guifang was bending down and pulling her coat tighter.

"Grandma?" Li Ao walked over quickly. "What brings you here?"

Liu Guifang, who was clutching the cloth bag in her arms, looked up when she heard the sound. Seeing it was her grandson, she smiled and nodded.

"Finished the exam? Are you hungry?" She took two steps forward to greet me. "I was thinking that other kids have their parents taking them, so I asked your Grandma Zhang to drive me over and see you. I'll also take you to get something nice to eat."

Li Ao was stunned for a moment.

He had casually mentioned a while ago that he had an exam today, but he didn't expect the old lady to not only know the route but also wait here right when the exam papers were collected. She had obviously planned this all along.

She's usually quiet, but she remembers his exam schedule better than the household accounts.

Now that she was here, Li Ao naturally wouldn't let her continue standing in the cold wind.

He took the cloth bag from his grandmother's arms and asked, "Where shall we go to eat?"

"Either is fine, I just got paid today."

Liu Guifang slowly pulled a bank debit card from her inner pocket, her tone unusually generous: "Tell Grandma what you want to eat."

Li Ao glanced at the card and smiled, "Let's go to the Hutchinson Dining Hall at the University of Chicago. There's not much good food outside."

After saying that, he picked up his cloth bag, turned around, walked past the students who were still checking their answers, and headed into the campus.

Liu Guifang paused in mid-air with the card in her hand, then shook her head and smiled.

She carefully put the card back inside her body, tightened her old handbag, and quickly followed after him.

……

In his previous life, Li Ao hadn't experienced much of the affection between grandparents and grandchildren.

As he watched Liu Guifang carrying her tray and carefully avoiding the crowd, and smelled the rich aroma of masala spices in the cafeteria, he suddenly felt a sense of unreality.

She was stunned for a few seconds before she came to her senses and quickly went to take the tray from her: "Grandma, sit here, it's bright by the window."

"Okay, sure." Liu Guifang carefully sat down opposite, afraid of bumping into the edge of the table.

There weren't many people in the cafeteria; in the distance, only a few University of Chicago students were gathered together, flipping through books and whispering.

The occasional clinking of cutlery against the porcelain plate was quickly swallowed up by the soaring Gothic dome, making the environment feel somewhat empty and quiet.

The grandfather and grandson sat facing each other.

Li Ao was probably hungry, as he lowered his head and ate large mouthfuls of rice.

Liu Guifang didn't say anything, but just held the paper cup and sipped the juice casually, her eyes fixed on his ravenous eating.

The aroma of steaming hot food carried a sense of awkward yet reassuring tacit understanding.

Seeing the empty plate, Li Ao pulled out a tissue to wipe his mouth.

"Grandma, I'll take you home in a bit, so you won't have to bother Grandma Zhang again."

Upon hearing this, Liu Guifang paused, her hand holding the straw still.

She hitched a ride with Sister Zhang from the church this morning; Sister Zhang works as a cleaner nearby and doesn't get off work until dark.

She was genuinely apprehensive about waiting for hours in this unfamiliar, empty foreign campus.

But then she thought of her grandson and hesitated, putting down the paper cup: "You've been taking exams all morning, and you still have to go to work this afternoon. It's too tiring..."

"I'm not tired, I just need to go back and take a half-hour nap." Li Ao stacked the empty plates together.

He wasn't exaggerating; with "deep sleep" as a guarantee, he could recover his energy in less than half an hour, maybe ten minutes.

As for taking Grandma back by bike—how heavy can an old lady be?

Seeing her grandson's insistence, Liu Guifang hesitated for a moment, then smiled and nodded.

It's good to go back early. I can go to the supermarket in the afternoon and make some chicken soup for my grandson tonight to help him recover.

After the meal, the grandfather and grandson chatted for a few minutes.

Liu Guifang was getting on in years, and after working hard for days, she couldn't help but doze off as she talked, leaning her head against the back of her chair.

Li Ao didn't bother her, and gently took out his draft notebook and spread it on the table.

Professor Brown hasn't been able to buy the remaining USAMO and IMO practice questions yet, so he's currently out of competition problems to work on and has decided to continue working on his previous mathematical derivations.

The newly optimized Hermite-Hadamard inequality's two-sided boundary can be further symbolized and axiomatically processed.

Not long after, Liu Guifang woke up groggily.

As soon as I opened my eyes, I saw my grandson scribbling something rapidly on a draft paper.

The old lady was momentarily dazed.

Why is this child so diligent?

So engrossed was he that he didn't even notice someone walking around him.

Liu Guifang dared not make a sound to disturb him, but she still couldn't help but lean forward and use her rough fingers to gently brush away a strand of hair that was blocking his eyes from his forehead.

Even though he moved very gently, Li Ao still stopped writing.

He closed the draft and looked up.

"Grandma, you're awake? Let me get ready and take you home."

"Okay, let's go home," Liu Guifang replied softly.

Li Ao quickly stuffed his stationery into his schoolbag, then grabbed a few unopened packets of ketchup from the plate and put them into his grandmother's old cloth bag.

While doing these things, he was still thinking about those axioms and boundary conditions.

On the way back to the South District, there were a few thugs loitering by the entrance of a convenience store, their eyes glazed over, looking like zombies.

Sitting in the back seat, Liu Guifang watched the chaos and subconsciously tightened her grip on the strap of her handbag.

Facing the cold wind, she remained silent for a long while before speaking in a muffled voice:

"Leo, study hard and get into a better school. Leave the South District, don't end up like Grandma, trapped in this awful place your whole life."

Li Ao steadily turned the handlebars, deftly avoiding an icy ditch by the roadside.

He faced the wind, his voice not loud but very clear:

"Grandma, please take care of yourself. I'll take you with me when I go."

……

Two weeks later, the AMC12 results were released. Li Ao unsurprisingly received a perfect score and successfully qualified for the AIME (American Invitational Mathematics Competition).

A week later, the math competition, which only included the top 5% of AMC12 scorers, officially began.

Inside the examination room, Li Ao received the exam paper and habitually flipped through both sides. After confirming that the printing was correct, he took out a mechanical pencil.

"Question 1: How many perfect squares less than 100,000 are multiples of 24...?"

The moment I finished reading the question, a mathematical image formed in my mind, and the answer was about to emerge.

"083." (Note: All answers to AIME questions must be three digits.)

The first five simple questions weren't even a warm-up; they were completed in less than twenty minutes.

The remaining ten difficult questions had increasingly longer stems and more complex conditions, but he was always able to quickly find the right approach and complete the solution.

He only glanced at the last, most challenging question.

It wasn't because the questions were too difficult, but rather because it was somewhat unexpected.

"Let triangle ABC be an equilateral triangle..."

"This year's final question was actually a plane geometry problem."

Generally speaking, the final AIME problem is mostly number theory or combinatorics, with few fixed approaches and extremely difficult.

Very few test takers succeed each year.

This year, we switched to plane geometry, which is slightly easier.

Without much thought, Li Ao quickly determined the approach of finding the extreme points and lines.

After adding a few auxiliary lines, the answer was given.

After finishing the exam, he looked up at the clock hanging at the front of the classroom.

Only half of the three-hour exam time has passed.

It was still early, but he didn't plan to hand in his paper early.

It's better to stay in the heated classroom than to go out in the cold wind.

I might as well just treat it as a different place to study.

He placed the pencil on the corner of the table, propped his chin up with one hand, closed his eyes, and continued to optimize the symbolization process of the weighted HH bilateral extension in his mind, trying to derive a simpler proof.

at the same time.

In contrast, most of the other candidates in the examination room had their brows furrowed.

Despite the cold winter weather, many people had sweat beading on their foreheads, which dripped onto their exam papers, leaving small water stains.

It's clearly stuck.

The proctor on the podium, holding a thermos, looked at the gloomy atmosphere below and couldn't help but mutter to himself:

How difficult was this year's exam?

His gaze swept over the sour faces, finally settling on the second-to-last row by the window.

The Asian boy in the gray hoodie was actually supporting his head with one hand, his eyes closed, and his breathing even.

Are they already asleep?

The proctor frowned.

"Giving up so early? Even if you really don't know, you could at least estimate a range based on the question and guess randomly between 000 and 999."

"Didn't the competition coaches ever teach exam techniques?"

He then got up and began to patrol the examination room.

As he strolled over to Li Ao, he deliberately glanced at the draft paper on the table.

The paper was unusually clean, with only a few scribbles in the corner.

The proctor looked away and shook his head inwardly.

Due to exam regulations, he couldn't offer any advice, and could only feel sorry for the candidate who "surrendered early."

Only when there was half an hour left did he clear his throat and speak up to remind everyone:

"There are only 30 minutes left before the exam ends, hurry up!"

These words instantly heightened the sense of urgency in the examination room.

Some people were so anxious they were shaking their legs, while others were frantically pulling at their hair.

Amidst the chaotic scene in the room, the Asian boy, who still kept his eyes closed, became the most out of place.