In Britain, the Noble Phantasm: Divine Key

Merlin subconsciously recalculated in his mind and found that, as Yanan had said, there were indeed 29 coins in total.

If that's the case, then where did the remaining coin go?

Cold sweat began to trickle down Merlin's forehead. He had never expected that the first question the other party would ask would be so sharp.

He stubbornly calculated it several more times, but found that the answer remained unchanged. The remaining copper coin seemed to have grown legs and run away; he couldn't find it no matter how hard he looked.

Looking at the composed Yanan, a sudden inspiration flashed through Merlin's mind.

If it's not a calculation problem, then it's very likely... a description problem!

Using loopholes in words to set traps for others is his most common trick!

If that's really the case...

Merlin closed his eyes, appearing as if he were asleep, but in reality, he was using illusion magic to simulate a real scene.

If Yanan really did set a trap for him with his words, then following the other party's line of thinking would only lead him into a dead end, and he would never be able to find the right answer no matter what.

Only by transcending words and letting the facts speak for themselves!

A moment later, Merlin opened his eyes, a confident smile on his face:

"There was no such copper coin at all. The nine copper coins spent by these three people already include the two that the waiter hid. That is, the discounted price of 25 copper coins plus the two that were hidden, totaling 27 copper coins. In addition, the boss returned the three copper coins, making a total of 30 copper coins."

Yanan raised an eyebrow slightly and nodded, saying, "Correct answer."

"Haha!" Merlin's face revealed a very smug expression as he chuckled mischievously, "I must admit, your question is indeed very cleverly designed. If it were an ordinary person, they would probably find it difficult to spot the trap and fall into your snare, getting stuck in a rut and never being able to get out."

"But what a pity, you've run into the brilliant, intelligent, beautiful, and resourceful Merlin. This little problem is no challenge for me at all, hahahahaha..."

Looking at Merlin's arrogant smile, Artoria frowned slightly. Her intuition told her that Merlin's method of victory was probably not exactly honorable...

However, she couldn't say anything, since Yanan hadn't set any requirements at the beginning; as long as Merlin could answer, it would be considered a success.

"Next question." Anahn ignored Merlin's laughter and said calmly, "Suppose one copper coin can buy one peach, and three peach pits can be exchanged for one peach. Now you have ten copper coins, so how many peaches can you eat?"

Merlin paused for a moment, then laughed even more exaggeratedly, clutching his stomach with tears streaming down his face: "You...you're not out of ideas, are you? You're even asking me this kind of question, or do you think you can't beat me, so you've simply given up?"

Yanan did not respond, his dark eyes calmly watching him.

"Alright, alright, it seems you're really out of ideas. I told you not to challenge the wisdom of the Great Sage." Merlin wiped away the tears from the corners of his eyes, cleared his throat, and said, "Then listen carefully, ten copper coins can buy ten peaches, the remaining ten peach pits can be exchanged for three peaches, and after eating them, the three peach pits can be exchanged for one more peach, so... that's a total of 14 peaches!"

"Are you sure?" Yanan asked calmly.

“Of course!” Merlin said confidently. Even a three-year-old could answer this question; he didn’t even need to use illusion magic to simulate it.

“Answer… wrong,” Yanan said in an unchanged tone. “The correct answers are 15.”

"Why?!" Merlin was dumbfounded once again.

“According to your explanation, you had one peach pit left over after exchanging peach pits the first time, and another left over after eating them all. You could then ask the buyer for a peach on credit, thus obtaining three peach pits, which would exactly offset the one you borrowed,” Yanan said calmly. “Wouldn’t that make 15 peach pits?”

"You...you're just making excuses!" Merlin pointed at Anan indignation. "Who gives peaches on credit?!"

“Really? I thought you were quite familiar with things like buying on credit,” Yanan said casually.

"Pfft!" Artoria couldn't help but burst out laughing.

Merlin blushed and exclaimed, "This...this is different! Besides, I've never run a debt. I make a living by my looks, I don't need to pay back anything!"

This is the first time I've ever seen someone so confident in refusing to pay back debts... Yanan's lips twitched, and he said, "Okay, let me put it another way. You buy these ten copper coins separately. The first time you buy three, the second time two, the third time two... and so on. In the end, you'll still have 15."

"So, is there a problem now?"

Merlin: "..."

Damn it, I should have just done a simulation!

Filled with frustration, Merlin forced a smile and said, "Alright, I admit defeat this time... but I have one last chance!"

If he can answer this last question correctly, he still has a chance to regain his dignity!

Merlin became serious for once, his eyes burning with the flames of battle intent.

This is no longer just a matter of victory or defeat; it concerns his wisdom and dignity as a great sage!

Although dignity wasn't that important to him... he was, after all, the great sage responsible for nurturing the king, a renowned magician, and he absolutely could not lose when it came to matters of intelligence!

Come on, let's begin the final showdown!

"The third question..." Looking at Merlin's eager eyes, Yanan paused for a moment, then a malicious smile suddenly appeared on his lips.

Merlin frowned slightly. For some reason, when Yanan laughed, he suddenly had a bad feeling.

"The third question is, if a plane is arbitrarily subdivided into non-overlapping regions, and each region is labeled with a number, then what is the minimum number of numbers required to make two adjacent regions have different numbers?" Yanan asked leisurely.

Merlin pondered for a long time before finally understanding the meaning of the words, and then he was completely dumbfounded.

Given a range of numbers, what is the minimum number of numbers required to make two adjacent ranges have different numbers? What kind of ridiculous question is this?!

He frantically tried to simulate it in his mind using illusion magic, but after trying for a while, he realized in despair that he simply couldn't finish simulating it!

The possibilities are simply countless!

Artoria, standing beside him, frowned deeply. Unlike Merlin, she didn't try, because her intuition told her that this seemingly simple problem was probably beyond human ability to solve.

The Four Color Problem, also known as the Four Color Conjecture, is considered one of the three great unsolved problems in modern mathematics, along with Fermat's Last Theorem and Goldbach's Conjecture. It was first proposed by the British university student Goodry in 1852 and was not finally proven until 1976.

This problem may seem simple at first glance, but its implications are incredibly rich. To prove this hypothesis, the University of Illinois in the United States used two computers, spent 1200 hours, and made 100 billion judgments before finally confirming it.

Looking at Merlin, who was covered in sweat, Yanan crossed his arms and remained calm.

Just kidding, if you solve this problem, I'll go back to the Land of Shadows immediately and never come out again!

"I...I think it's eight." Under Anan's gaze, Merlin could only bite the bullet and randomly say a number.

“Wrong answer. The correct answer is four,” Yanan said calmly.

"Why!?" Merlin asked unwillingly.

“Hmm… this question is rather complicated to answer, and you might not even understand it.” Anan’s unintentional remark seemed to pierce Merlin’s heart like a knife. “If you think it’s wrong, you can try to give a counterexample—though it’s unlikely to succeed.”

You're kidding me. It's a miracle he can even remember Qi Jiguang's Mandarin Duck Formation, let alone the proof of the Four Color Theorem.

Besides, that thing can't be proven by human effort anyway.

Merlin, unconvinced, tried using illusion magic, but after a full hour, he still couldn't find a single counterexample.

Could it be... that there really are four answers?

Merlin looked at Anahn with trembling eyes, deeply feeling the crushing pressure emanating from the intellectual superiority of Anahn.

His head lolled to the side, his eyes were vacant, his expression was deathly still, and his whole person seemed to have turned into a gray photograph.

"It seems the result is already obvious." Yanan looked at Merlin, who was frozen in shock, and shrugged: "Sorry, Merlin, you lost the second round."

Chapter Thirteen: News of the Day of the King's Selection

The next two matches were not played because Merlin conceded defeat.

He left as if he had lost his soul, his eyes lifeless, muttering repeatedly, "14 peaches... 15 peaches... 4 numbers... 8 numbers... adjacent... different..."

Looking at Merlin's weathered figure, a hint of worry appeared in Artoria's eyes. After all, Merlin was her teacher and best friend who had been with her for more than ten years, and she felt a little sorry for him seeing him like this.

"Don't worry, those heartless guys will recover soon enough," Yanan said, stepping forward to comfort him.

Artoria nodded, hesitated for a moment, and said, "Teacher, isn't your method of winning a bit...?"

To be honest, she felt that none of those questions were answers that a normal person could answer.

"Despicable, is that it?" Anaen smiled at Artoria, easily reaching her head with his nearly head-high height. "This is the first lesson I'm going to teach you, Lily. You have to use different methods against different opponents. Be even more despicable against despicable people, and even more cunning against treacherous people."

"A king's image is one of integrity and uprightness, which will win you the love and respect of the people. But your methods cannot be like that, because your opponents are all dirty guys, so you must use even dirtier methods to defeat them, otherwise you will fail the people's expectations."

"But teacher, I don't understand. I don't know how to use the... dirty methods you mentioned."

Artoria received the most orthodox knightly education from a young age. Justice, fairness, trust, humility, understanding... More than ten years of upbringing made these things almost part of her life creed. So for a moment, she didn't know how to understand the "filth" and "despicable" that Anaen spoke of.

“It’s alright, I’ll teach you all these things later. Since you’ve called me teacher, I can’t let you down.” Yanan smiled, but there was a hint of guilt in his eyes.

Artoria gave a soft "hmm," her head lowered, a complex expression appearing in her azure eyes.

……

……

A month later, a bombshell piece of news spread like wildfire throughout Britain.

The day of the election is fast approaching, and the location is Taylor Bill!

Countless knights rode their warhorses to Taylorbill overnight, and everyone was eager to show off their skills at this grand banquet.

Not everyone's goal was the Sword in the Stone. Some intended to use this opportunity to demonstrate their strength and gain the favor of the future King of Camelot; others were curious about who would ultimately claim the throne that had been vacant for over a decade; and still others, whose origins were unknown, remained hidden from public view, quietly observing this royal selection feast.

With various motives in mind, these guys gathered in Taylorbil, a small town on the British frontier, and it was the liveliest time in the town's history.

Chapter Fourteen: The First Step to Changing the World

Artoria looked at herself in the mirror.

With her long, golden hair piled up, a masculine vest and trousers, and arm and leg armor signifying her knightly identity, apart from her holy blue eyes and fairy-like exquisite face, she was completely different from her former self.

The chivalrous spirit she cultivated from childhood filled her eyes with a heroic air, making her look more like a handsome fairy knight. Unless someone is very familiar with her, no one would recognize her now—at most, they would mistake her for an older or younger brother.

The day of the election is fast approaching. In order to avoid revealing her identity, she must appear in this disguise from today onwards until she pulls the sword from the stone.

More than a decade of preparation is about to come to an end.

But am I, in my current state, truly qualified to pull the sword from the stone?

Looking at her fair hands, which hadn't developed any calluses despite daily sword practice, a complex expression appeared in Artoria's eyes.

She took a deep breath, turned around, and walked out of her room.

She arrived at a wooden cabin in a corner of the manor, looked at the wooden sign with the words "Yanaen" written on it, and hesitated for a long time.

No, there's no need to hesitate any longer; perhaps this is the best way...

A look of determination gradually appeared in her eyes, and she gently knocked on the door.

Red Dragon's heart was pounding rapidly, as if only a moment had passed, yet it also felt like decades had gone by.

Artoria suddenly snapped out of her daze and looked at the still tightly closed door in front of her.