The three holy places, plus the two major dynasties, each sent an innate martial artist to the front to explore the way.

The five men entered it and searched for it.

About a quarter of an hour later, five people came out one after another, and one of them said, "Your Majesty, we entered a secret passage, and the secret passage continued to expand, and a hall appeared. In the center of the hall, there was a huge dragon with a ball in its claws. ”

"There's no danger there!"

"Since there is no danger, let's go down!" said the Martial Emperor.

With that, he took a step forward and entered the underground passage.

The warriors of other forces were also unwilling to lag behind and entered the underground passage one after another.

At the moment of entry, they were afraid of each other and guarded, but they tried to avoid confrontation.

Celestial warriors, transcendent warriors, the combat power is too terrifying, the destructive power is too strong, almost tearing everything, destroying everything, there have been several times when the ruins have been opened, it is because of the competition between the heavens and men, under the strong destructive power, the ruins are dilapidated and seriously destroyed.

Afterwards, it's a pity.

Therefore, before opening the ruins, many forces swore with their Dao hearts that they would not take it lightly in order to protect the ruins.

But there are exceptions to everything, and it is impossible to be too careful.

The passage outside is relatively narrow, but you can follow the cracks in the ground, the more you go underground, the more you feel that the ground is wide, and after walking for five miles, a huge hall appears, and everyone enters it.

The hall was huge, 100 meters wide, with a three-meter-high statue of the dragon in the center, and a meter-sized ball on the dragon's right claw.

The ball was rolling up and down, and it seemed to be very spiritual.

On the ball, there is a complex map with land, sea, and a country, and the name of the country written on it.

Everyone stepped forward, carefully observed, and carried out archaeological research.

Soon, at the base of the statue, I saw a line of text, "Use four colors to mark the different countries on the planet, so that the borders of the countries are different!"

"It's the law of four colors!"

Saint Chev said: "Among the ancient ruins, among the civilizations born, there is a civilization called the civilization of science and technology, in which mathematics is the foundation, and complex technologies and weapons have evolved...... Of course, most of the technology is useless to us, but there are some interesting things that can improve people's lives!"

"In mathematics, there are many problems, among which is the law of four colors, which is quite brain-burning!"

As she spoke, the Saintess Cheph explained some of the principles of the four-color law.

On this sphere, there are more than 200 countries, and they have to use four colors to color these countries, and they are next to each other in different colors.

"Some head burning!"

Emperor Wu said and calculated.

Other martial artists are also calculated.

Begin to color the balls, look rough and inconspicuous, and then look at it is still inconspicuous, but after careful calculation, it is indeed difficult. One hour, two hours, three hours, four hours...... A day has passed, and there is still no answer, and it still can't be perfectly colored.

............

"Congratulations to the four princes, there is hope for the future enthronement!"

In the imperial capital, the world became quiet as the big guys left.

Suddenly, Li Mu had a feeling that there was no general in Shu, and Liao had turned into a pioneer.

"I'm just lucky, I just happen to be the fourth!" the fourth prince was much more modest, "I'm just in charge of the country, and I'm not the prince yet, even if it's the prince, it may be abolished!"

The father's desire for power is very great, and his control over power is great, and in the face of such a father, it is actually difficult to be a prince.

If he does too well, the emperor will be suspicious, and will wonder whether the crown prince is about to seize power, whether he is going to empty the emperor; if he hides himself, hides himself, and does things mediocrely, the emperor will wonder if the crown prince is incapable and whether he should replace the prince.

It's not excellent, it's not mediocre, and it's hard to grasp the degree.

Now he is in charge of the country and has great power, but the fourth prince does not have much confidence that he can survive to the position of the crown prince or even the emperor.

"Since the emperor has decided, it will not be changed easily, and the imperial court will not be able to withstand the toss!" Li Mu said: "Now stability is overriding everything. ”

"I hope so!" said the fourth prince, but his confidence was low, "Go to the mansion and have a few drinks!"

"Good!"

Li Mu nodded.

When they arrived at the mansion, they drank wine with each other, pushed glasses and changed lamps, and the friendship was deepening.

The emperor is gone, and many celestials are gone, making the originally unstable world even more unstable, and these burdens need to be on them.

While drinking, news suddenly came from the summons order.

The fourth prince listened to the news and said with a smile: "At the gate of the ancient ruins, they came across a sculpture, the sculpture is a divine dragon holding a ball, there are more than 200 countries on the ball, and four colors should be used, and the countries adjacent to each other should have different colors!"

"The question is simple! It's really simple at first glance, but if you think about it carefully, it's not simple at all!"

"Those celestials, transcendent martial artists, have calculated the time for more than a day, and there is still no clear answer!"

Li Mu said: "This is a four-color problem!"

The fourth prince said: "It is said in the ancient ruins that these are three major mathematical problems, which seem simple and difficult to prove!"

"Actually, the hardest thing to prove is that one plus one equals two!"

Li Mu said with a smile.

"Wait a minute!"

When the four princes arrived in the courtyard, they waved their hands, and immediately the soil was adsorbed, falling on the palms of their hands, and the true qi was compressed, constantly squeezing, and gradually forming a round ball, on which there was a clear division of countries, and the name of the country, which was extremely similar to the size and size of the ball in the ruins.

"This is the iron ball in the ruins!"

Li Mu looked at Tieqiu and said: "Actually, it's hard for them, they have excellent calculation ability, and they can come up with the answer in ten days at most!"

In the previous life, the law of four colors could not be solved by the human brain, and finally relied on the computer, brute force cracking, one permutation and combination, from tens of billions of permutations and combinations, constantly eliminating, and finally finding the correct answer.

In my previous life, relying on the human brain, I really couldn't solve this problem.

But in this world, when he arrived at the Great Grandmaster, he condensed the Yuan Shen, and the Yuan Shen had a huge computing power, Li Mu's calculation power in the early stage of the Great Grandmaster was 100,000 times per second, the Great Grandmaster's consummation was 300,000 times per second, the half-step Celestial was 1 million times per second, and the Celestial Realm was 10 million times per second.

As for the perfection of heaven and man, the transcendent realm, the calculation ability is even better.

Genshin, the equivalent of a computer, has terrifying computing power.

It is estimated that the four-color law will not be able to withstand those strong people, and it will take ten days at most to crack it.

Li Mu looked at the ball casually, and suddenly felt familiar, the national topographic map on it, as well as the terrain of the continent, seemed to be extremely familiar, and the geographical knowledge of the previous life emerged.

"It's a globe!"

PS: The third update has arrived.