'There are eight gold coins and one balance. However, only one of these gold coins is said to be a fake. The counterfeit gold is slightly lighter than the real one and can be easily measured by the balance. What is the minimum number of times you can find this fake gold coin on the balance? If you answer this question incorrectly, you will be forced to return to the entrance.

　...It's a complete riddle. Well, that's a decent one.
　It's a problem that only takes a moment's thought to figure out. The correct answer is... No wait.
　The answer I've reconsidered is flowing along with the magic power of the water attribute.

I'm not going to be able to get a hold of you.

　I knew it! A really bad character.........

''Lord, what was the answer now?''

　Amber asks. Hmm? Oh, you couldn't tell because you floated it in your mind.

'How many times do you think it normally takes?'
'Divide the four pieces into four pieces and weigh them on the balance, once. The four lighter pieces are divided into two pieces, and then measured twice more, and finally the two lighter pieces are counterfeit gold, for a total of three times.
'Yes, that's right. But if the three pieces are placed on either side of the balance, and if they balance, one of the two remaining pieces is a false gold coin, so you only need to do it twice. If they are not equal, the lighter one is placed on each side of the balance, and if they are equal, the remaining one is a false gold coin. Either way, it only takes two. Normally, this would be the correct answer.

　Usually.

"More than once"?
'There's only one correct answer. If you take two of the eight cards and measure them with the balance, "if you're lucky," you'll get it right once.
"With a little luck...
You didn't specify 'sure' or 'one shot' in the question, did you? It's a question of answering the minimum number of times you've used the balance.

　This is the ruins of Babylon, after all. The problem is disgusting. I think that's what the doctor would think. We've known each other for a long time now, so I don't like the idea that I can somehow understand what he's thinking.... I've become soiled.



　And after that.....


The following formulas are based on certain rules. Answer the number corresponding to the □.

36 = 1
108 = 3
2160 = 2
10800 = □.



　When there was a relatively decent question like "What's the point?
　In the end, there was no trick and the answer was 5.
　Either way, this is not a riddle, but a real riddle. It's certainly not difficult, but it's tricky to get back to the entrance if you make a mistake. The wall closes again, and it's replaced by a new problem. I'll give you a quick rundown.



"There are two unbreakable magic ropes that burn up in exactly one hour when lit at the end. How can I accurately measure 45 minutes without leaving any rope behind?



A man was preparing four fish for dinner when three cats came and took one of each and ran away. The man's family was a family of four, and they all got to eat a fish for dinner without any problems. 'Why?'



There are 27 gold coins in the bag. If three adventurers were to divide them equally and still leave at least five pieces in the bag, how many pieces would each of us be able to get?



　It is a true riddle. I don't want to go back, so even if I come up with an answer, it takes me a long time to reconsider, to see if there are any oversights or traps, which makes me feel as if I am dancing on the hands of the doctor.
　By the way, the answer to my earlier question is



'One of the two ropes will be lit at both ends and the other will be lit at one end only. When the ropes lit at both ends have burned out, the remaining end will be lit as well, and when they have burned out, you have 30 minutes plus 15 minutes for 45 minutes.



'Three cats "plus" more escaped, so there are seven fish in all. Nothing wrong with that.



'Nine pieces. Divide them up evenly, and one of you can get the whole bag.



　And this is how it works.

　Ping-pong ping-pong ping-pong.

　When I broke through the last unattributed room, there was the same as usual, a transporter camp with six stone pillars standing in it.

''Finally......... After making it take you so much time at all........''

　I know it's just a joke of a joke from the doctor anyway, but I'm supposed to put myself in the shoes of those who have to go along with him. Disgusted, I poured magic power into the six pillars of magic stones and stood with Amber in the center of the transporter formation. The non-attribute magic power is poured underneath their feet and the transporter formation is activated.



　The rush of light subsided, and when I opened my eyes, it was the usual scene of Babylon. The trees rustled in the wind and a sea of clouds spread out in the distance.
　As I scanned the area, I saw a building beyond the trees. Now, is it a "storehouse" or a "library" or a "laboratory"?
　I walked out of the transporter camp and headed towards the building, and soon I knew what it was from the full view that came into view.
　The building was circular in shape, shaped like a tuna can. It was fully glazed, and you could see the whole inside through the windows. From there I could see how far the interior of the building was filled with bookshelves and piles of books.
　It's a library. There's no doubt about it.
　You walk around the perimeter of the building and look for the entrance. Soon we are greeted by a large, luxurious door.
　We open the heavy Kannon (Japanese traditional medicine) door and find another door behind it, which we also open to enter the Library.

''Ugh........''
This is...

　I'm in raptures with Amber. Books, books, books, books as far as the eye can see. The stacks of books are lined up more than ten meters high, but they are curved to match the outer walls, making it look like a maze.
　There are books at an unreachable height, but how do you get to them? There are no stepladders or ladders around....
　Stepping on the red carpet under my feet, I decide to head to the center of the circle for now. I can't head straight for it, though, because it's so intricate. Obviously, this is a misplacement of the bookshelves.
　Nevertheless, if you look at the ceiling, you can find the direction of the center through the radiating seams, so you can rely on that to keep going.
　After a while, the area suddenly opens up and I can see desks and chairs everywhere. There was a pile of various books on the desk, and a girl was sitting on the sofa behind it.
　She looked down at the book she was holding and didn't even look at me. Her chestnut-colored hair was cropped into a short cut, and her glasses-wearing profile had a look in common with the other Babylon Numbers. The clothes she's wearing are the same as everyone else's, and she's probably the manager of the 'library'.

''Um........''
"Atto, please do not speak to me as I will be finished in about 30 minutes.
Oh, yes....

　There's no way to get around it. It's a complete waste of time. It's no use, let's wait. The sound of a girl turning pages drifts through the quiet space. I'm nowhere to be found, so I casually pick up a book and open it up.

"I can't read...

　What language is this? It's not an ancient magical language or an ancient spirit language. Ancient Partheno?

"Readings/Ancient Partheno.

　I can read it. I can read it. It's so difficult to understand........ It's kind of like a report on thinking and researching about monster beasts.
　Maybe it's because I activated "Reading", I was able to read the titles on the spine cover in places. That whole thing must be a book written in the ancient Partheno language.

'Interference and Considerations in Magical Fluid Control'

Herbology and Potions.

"Nighttime Guidance for Beginners.

　Oi. I reached for the blatant title and flipped through it, and sure enough, it was a how-to book.

Let's start by eliminating the tension so that we can enjoy each other's company. If you're not underage, it's not a bad idea to drink lightly and take a little help from alcohol. But if you drink a little too much, you'll ruin it. Next, the other person...'

　Hmmmm........... I see.....
　I have a feeling this will work surprisingly well.......... What, is this........really? No, but hey, it's a hurdle... This "casual" thing is hard to do....

"Since you're reading Nani?
Wow!

　I jumped up at the voice behind me. Surprise! Huh? It's been 30 minutes already!
　The girl opens her mouth, tilting her head quizzically in my direction.

You are the one to go to the Library of Babylon. I am the terminal that manages this "library" and my name is Iris Femme. Please call me Pham.
Oh, yeah, fam, you know. I'm Fuyao Mochizuki. Nice to meet you.

　I put the book back in place with my back hand while answering. Did you see.........

"You are here to solve the doctor's problem, I take it that you have met the requirements. You have fulfilled the requirements, and aircraft number 24, Iris Femme, is now yours. Goodbye, Master.

　Oh, I knew it was the doctor's work. You don't have to make something like that. Well, it's better that I'm not exposed to unnecessary erotic attacks.... Ha!
　I noticed this next development and tried to brace myself, but it was already too late, and I was already losing my lips to Fam. Quickly, a tongue was inserted and violated my oral cavity. That act, which was easy compared to that of Liora in "The Walls," ended quickly.

''Registration complete. We have memorized the Master's genes. From now on, ownership of the 'Library' will be transferred to the Master.

　d*mn, I'm not a good learner, am I? I knew this was going to happen. Well, there's no choice not to, so I have to do it sooner or later, so it's better than getting beaten up in a weird situation.......

'So, how well do you currently have Babylon in place?
'What? Well, there are six of them, the Garden, the Workshop, the Alchemy Building, the Hangar, the Wall, the Tower, and this Library is the seventh.
Nal. Well, let's head in that direction.

　As he typed something into the terminal on his desk, the 'library' began to move quietly. It was probably heading to dock with the other Babylon in the skies above Brunhild.

'Master. I have a request. I would like for this 'library' to receive new books...''
'Do you need any more books? I mean, how many books are there?
I'd say it's roughly 20 million books, maybe less.

　Two. I thought the Library of Congress in Japan has about 10 million books. As I recall, it looks like it's going to be about 35 million if you add up all the journals, newspapers, non-book materials and so on.

I've already read it, and I would like to read a new one. Please do so as soon as possible.
Read... 20 million books?
'If you read a book in an average of two hours, and it's been going on for five thousand years, that's about it.

　No, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no. Sheska and Flora have been sleeping in a sleeper for years, and even Noel in the "tower" is still sleeping!

'I don't work so much. Still, after 5,000 years of operation, it's starting to go bad. Well, if we can find a lab, we'll be able to maintain it properly.

　You've been reading books for 5000 years.... You're a hardcore book lover. A hard-core bookworm, you say? That's outrageous.
　Anyway, I should report that you found the library that Lean has always wanted to read. I'm sure that Leanne will be able to get into it, though.