Conan: Another Famous Detective

Conan and others looked at the jam.

I saw that there was indeed some content on the card.

Code: 21 23 18

6 24 12 8 21 16

15 8 17 22 18

"What...what is this?" Xiaolan looked at the numbers with a confused look.

"From the current point of view, it should be some kind of code or something. The English word at the beginning has made it very clear." Conan frowned at the numbers and asked:

"Is there anything else in the envelope besides this card?"

Yu Gongming dug through the envelope again, and then showed his hand without anything to everyone: "No more, just this card."

"So, the only clues we have so far are these numbers..." Conan stared at these numbers with a gleam in his eyes.

"It seems that if you want to continue to pursue this matter, you can only solve this code first." Yu Gongming said solemnly.

"But, do these numbers have any meaning?" Xiaolan looked at the numbers on the card, silently calculated for a while, and shook her head slightly:

"Whether it is arranged horizontally, vertically, or diagonally, there is no pattern between the numbers,"

"Will the numbers need to be converted into English letters?" Mengyu proposed a new guess.

"Then give it a try." Yu Gongming said, and asked the waiter at the coffee shop for a note:

"Assuming that these numbers do represent English letters, then generally speaking, the 26 letters should correspond to the numbers 1~26 one by one. In other words, the above numbers converted into English should be..."

Code：U W R

F X L H U P

O H Q V R

"That should be it..." Yu Gongming checked the numbers and displayed the converted English on the table.

The four people looked at the English translation and fell silent for a moment.

For a long time, Xiaolan couldn't help but look at Conan: "Conan, have you figured it out?"

Conan shook his head slightly: "Not yet. I have tried many possibilities, but I can't come up with a regular combination."

"Have we misunderstood? It's not actually converted into English?" Meng Yu frowned.

"I think the idea of ​​converting to English should be correct. Look, none of these numbers exceeds 26. In other words, all numbers can be replaced by the corresponding English letters. I don't think it is a coincidence." Hanemiya Mingdao.

Conan pushed up his glasses: "If it is English, then these English words also have no rules. There is no way to form an understandable meaning. Maybe we have overlooked something..."

Yu Gongming took the card again, carefully looked at the contents on it, and recalled what he had read about passwords.

"Wait a minute!" Meng Yu suddenly clapped her hands: "Didn't Xiaolan also draw numbers when she was drawing the lottery? Is this related to this secret code?"

"Huh?" Both Yu Gongming and Conan's eyes lit up, and they immediately took out the paper ball he had secretly taken from the box from his pocket.

"The number on the paper ball is 9..."

"Nine..." Yu Gongming added this number to the secret code.

After a while...

"No, I have used addition, subtraction, multiplication and division again, but there is still no pattern." Yu Gongming rubbed his forehead:

"Either we didn't find the right method, or the winning number has no meaning, or it has meaning, but it is not used to solve the code."

"If there is no correlation between the winning number and the secret code, that is to say, the only information we can rely on to unlock the secret code is the content on this card?" Mengyu tilted her head:

"There is only the content on this card..." Yu Gongming looked at the card.

"Is there anything else on there that we haven't used?"

"If there is something that has not been used yet, it should be this [Code]." Mengyu said.

"Code means password, code, code, etc. This should be the prefix description of this string of digital codes, right?" Xiaolan said.

Meng Yu snorted: "Probably? Is it just that the guy who designed the code looks down on us? This kind of thing can be seen as some kind of code even without adding a prefix. Adding this word is quite redundant."

Yu Gongming, who was deep in thought, was startled when he heard this.

"Superfluous... superfluous... meaningless... can you say that!?" Yu Gongming's eyes gradually lit up!

"Huh? What did you think of?" Mengyu asked curiously, and Conan and Xiaolan also looked over at almost the same time.

Yu Gongming smiled slightly: "I have solved this code!"

"Eh? Has Hanomiya-senpai untied it yet?" Xiaolan said in surprise.

Conan was a little surprised when he heard that Yu Gongming had solved the code.

"Obviously no one had a clue just now, why did Yumiya suddenly solve the code?" Conan recalled the scene just now.

"Just now it seemed that Mengyu was complaining that the guy who designed the password added a prefix in vain...and then...huh? Wait..."

A flash of lightning flashed across Conan's mind, and he immediately reached out to take the code card from the table and looked at it carefully.

After more than ten seconds, Conan's lips curled up: "I see, that's what happened!"

"Conan?" Xiaolan saw the change in Conan's expression and immediately realized something.

"It seems you have thought of it too." Yu Gongming smiled.

"Yeah!" Conan nodded heavily.

"So, two famous detectives, can you help us answer our questions?" Meng Yu asked with a smile.

"Of course, speaking of which, I would also like to thank Mengyu for inspiring me with your words!" Yu Gongming said with a smile.

"Oh? Which sentence?" Meng Yu was confused.

"That's the sentence that complained about the redundant prefix of [Code]." Akira Hanamiya explained.

"As you said in Mengyu, even if this prefix is ​​not added, it does not affect our understanding that this is a code, so this [Code] can be completely removed."

"Yes, after removing this, if you look at the numbers again, you will find that the first row of numbers has three digits left, just like this..."

Conan placed a note on the table. On the note was a code that no longer contained the [Code].

"Eh? Wait a minute, if you look at it this way... is it the Caesar code?" Meng Yu said in surprise.

"Caesar code? What is that?" Xiaolan asked doubtfully.

Dream Language explained: "The so-called Caesar cipher is a substitution encryption technology. All letters in the plaintext are shifted backward or forward by a fixed number in the alphabet and then replaced with ciphertext."

"Like this digital code, if I understand correctly, since there are three spaces left, the English we convert through numbers should also push three letters forward or backward on the alphabet."

"That's right, I tried it. If I push all the letters forward three letters, I can get an understandable answer."

As Yu Gongming spoke, he had already shown the replaced English to the three of them.

(empty): R T O

C U I E R M

L E N S O

"At this point, as long as you use the idea of ​​​​a fence code, instead of reading the letters first left and right and then up and down, but first up and down and then left and right, you can get the final answer."

"That's it!" Conan slapped the answer on the table.

【CLUE IN RESTROOM】(The clue is in the public toilet)