Different from the serious atmosphere of various countries, the atmosphere of the Chinese national team seems to be much more relaxed.

"Zhengxuan, this way!"

Bi Qi waved his hand to Ma Zhengxuan, who had just walked out of the examination room.

"I knew you wouldn't turn in until the last second. Bi Qi patted Ma Zhengxuan's shoulder and said with a smile, "If you want me to see it, it's most comfortable to hand in the paper in advance, there is a saying......

"It's cool to hand in the paper for a while, and it's cool to hand in the paper all the time!"

Ma Zhengxuan smiled and glanced at Bi Qi lightly, "Forget it, I'm not like you, I like to pretend to be forced at all times." ”

"How can the matter of a scholar be called pretending!" was broken by Ma Zhengxuan, Bi Qi was a little sneering, "By the way, the third question, how long did it take you to come up with an idea?"

Ma Zhengxuan thought for a moment and replied, "About five minutes." Isn't it just using the Menelauss theorem and affine exchange group that Mr. Gu once told us!"

"Who's to say it's not!" Bi Qi slapped his thigh suddenly, "But I thought about it for more than ten minutes before I came up with it, I'm really ashamed!"

"It's okay, it's a little slower, but it's harmless. ”

"But...... I really can't forgive myself!!" Bi Qi sighed as he looked up to the sky.

A street fighter passing by: "???"

…………

Gu Lu didn't ask everyone about their performance in today's exam for the time being, but took them to dinner and arranged for them to go back to the hotel.

And he himself took advantage of the quiet night to come to Imperial College London.

By brushing his face, Gu Lu successfully borrowed a library card again and came to the library.

is still the book "An Introduction to the Theory of Numbers", Gu Lu casually found a vacant seat, and while flipping through the book, he revised and revised the content of his paper.

One was busy until late at night, and when Gu Lu was about to return the book and leave, he found that there were already several female college students with different looks sitting next to him, and he was completely surrounded in the middle.

"Handsome guy, do you have time tonight?" A girl with an explosive figure approached Gu Lu, her long golden wavy hair rubbed against Gu Lu's face, and said in a very charming tone, "I heard that there is a hotel nearby that has launched a couple's room, do you want to experience it with me." ”

"Sorry, no money. Gu Lu directly relied on the advantage of his long legs, trotted and left in a hurry.

"I'll pay, I can pay!!" the best girl shouted loudly at Gu Lu's back.

…………

Gu Lu, who has lived abroad for many years, has long been accustomed to this.

I went back to the hotel and slept beautifully, got up at seven o'clock in the morning the next day, and after having breakfast downstairs, Gu Lu came to the office building again to participate in today's topic selection meeting.

Compared with yesterday, today's topic selection meeting is much more tense.

After all, yesterday, many members of the competition powerhouses were brought back to life by the third geometry problem.

Those competing powerhouses will never allow this to happen again.

At the beginning of the meeting, there was a strong smell of gunpowder.

Today's 20 questions also have combinatorial math problems similar to yesterday's geometry problems.

The leaders of more than a dozen countries, led by the United States, South Korea, and Yingguo, proposed to Chairman Andre to remove the topic, but some people in that group of small countries still insisted on keeping the topic.

With the advantage of numbers, the topic was not eliminated in the first round of screening.

But in the second round of voting, that question was finally brushed down.

Finally, after discussion, today's three questions are:

The fourth is a plane geometry problem, the fifth is an algebra problem, and the sixth is a combination of math problems.

The difficulty of the three questions is Normal, Medium, and Hard.

Seeing that these three topics were selected, many team leaders of major countries breathed a sigh of relief at the same time.

These three questions are their team's favorite form of questions!

The next step is to provide solutions to the questions and develop scoring rules.

At this point, many coaches looked at Gu Lu with melancholy eyes.

"Team Leader Gu, do you still have that simple new solution to the three questions this time?" Leader Yingguo walked up to Gu Lu and asked tentatively.

What is he most afraid of.

It was Gu Lu who suddenly came up with a simple version of the new solution to the problem, and then someone proposed to change the topic, in case this proposal was passed, and the combinatorial math problem was replaced, then they, the big countries in the competition, really wanted to cry without tears!

That's why they are so worried that Gu Lu will stand up and add variables to the exam questions that have already been chosen.

However, to everyone's relief, Gu Lu shook his head and denied with a smile, "Not this time." ”

"Is there really nothing?" Leader Yingguo wanted to make sure again.

"Not anymore!"

The corner of Gu Lu's mouth smiled bitterly.

Looking at me one by one with the eyes of a thief, am I so unreliable?

Provide answers, develop grading criteria, translate test questions.

When the test papers translated into various Chinese languages were placed in front of everyone, the leaders of several major competition countries put down a big stone hanging in their hearts.

Park Changqu was also in a very good mood, and said to Gu Lu with a smile, "Team Leader Gu, I take back yesterday's words, our bet contract still counts!"

Gu Lu: "???"

He turned his head and looked at Park Changqu speechlessly, "When did you tell me to give up the gambling contract?"

Park Changqu: "Just what I told you yesterday, but at that time, you happened to be absent, so you may not have heard it." ”

Gu Lu: "......"

Well, it's good if you're happy.

…………

In the afternoon, the lounge.

The leaders of the top countries in the competition, such as the United States, Yingguo, Russia, etc., leaned on the back of the chair in a comfortable mood.

Wine was poured into the glass, and while chatting, he stared at the screen displayed on the monitor.

At one o'clock, the IMO exam officially began the next day.

After yesterday's experience, Bi Qi did not feel the slightest nervousness at the moment, but was full of excitement and expectation.

The first question is geometry.

Oh, this is simple, first the inverse of Ptolemy's theorem, and then a Dessaq theorem.

What, not enough?

Let's take another double meaning of the Elcos theorem. (Elcos Theorem 1 and Elcos Theorem 2)

After three moves in a row, whether this question is a weak girl or a muscular hunk, he can be foamed at by Bi Qigan's mouth.

The second question is algebra questions.

It's still Fermat's theorem!

No matter how many layers of vest it replaced, Bi Qi still saw through the essence of the question at a glance.

Bi Qi has done countless questions about the topic of Fermat's theorem, although the problem in front of him requires the deformation formula of Fermat's minor theorem, which is barely a little new.

It seems that it is because of the gentle use of washing hair in the morning, Bi Qi has been silky smooth all the way, without the slightest hindrance.

An hour and a half after the start of the exam, Bizzy was left with only the sixth question.

[Given the integer N≥2, N(N+1) football players with two different heights stand in a row, and the team coach wants to remove N(N-1) from these players, so that the remaining 2N players in this row meet the following N conditions:

(1) There is no other player between the two tallest players among them

(2) There are no other players between the third and fourth tallest players

…………

(n) There is no other player between the two shortest of them.

Proof: This can always be done. 】

…………

PS: The above question is the original IMO question, you can try it...... Uh, forget it, the answer will be announced directly in the next chapter!