"What a strange puzzle!" This was Lu Feng's reaction when he first saw the content of the puzzle. At first glance, the question is similar to the true or false judgment question in the Olympiad, but the question type is obviously an unknown problem solving, especially what "I will know if you know", what is this the meaning of shrimp?

"Leave it to me, leave it to me!" Anyway, Nanami volunteered, and Lu Feng didn't bother to worry about anything. Even if you don't know the conditions, if you use two numbers within 1 to 100 as the basic conditions, it is only 10,000 possibilities, write a dozen lines of program code, and you can exhaustively enumerate them in seconds, so you really don't need to worry.

On the contrary, this relic is not just the simple functions of the Divine Digital Machine and the Prophecy created by the agent. Judging from the vast and complex labyrinth, as well as this fire gem containing amazing energy, there should be a deeper secret.

As Lu Feng expected, Nanami soon had an answer.

"Cut~ Bai is happy!" Nanami had a disdainful expression on her face at the time, and she almost lost her noble woman's demeanor than her middle finger. "It's a long-standing puzzle that Dutch mathematician Hans Freudenthal published in 1969 and has been called 'the most unlikely puzzle'. ”

Then Nanami gave a rough description of its solution. The conditions for those two seemingly nonsense sentences are indeed valid conditions: the first sentence can deduce that two numbers cannot be prime, and the second sentence can deduce that the sum of two numbers is odd, and cannot be the sum of 2 and some prime number. One of them makes a small use of Goldbach's conjecture. According to this condition, many group solutions can be obtained, but the more accepted ones are 4 and 13.

"Countless people have already done it, it's a waste of Miss Ben's time!" Nanami complained in annoyance.

I already knew what the girl was, and Lu Feng could only smile bitterly, but at this time, Takeuchi Suna's words aroused Nanami's interest again, and the previous unhappiness was swept away: "Even if you get the result, how can this result be entered into this gem?"

yes, this gem doesn't have a keyboard, where should this result be entered?

Nanami stroked the incense fan thoughtfully: "This question is worth studying!"

Seeing this scene, Lu Feng and Thoma both gave Takeuchi Suna a "you are amazing" look, and they were really frightened by Nanami's exuberant energy. Lu Feng even sometimes thinks that Izumi Mitsukoro has a strong desire for knowledge, so much so that the badges he gets are all knowledge badges, but compared to Nanami, it seems to be far behind.

At the bottom of the sea, the giant whale beast floats up once a day and spews a huge amount of water. With the movement of the giant whale beast, the Iron Island also began to shake slightly.

I remember that when the Demon Beast split the island of Failu into more than a dozen pieces and drifted across the ocean with the black gear, except for a few islands that were successfully destroyed by Yagami Taiichi and the others and returned to the Infinity Mountain, the rest of the islands either continued to move in an unknown direction, or stopped in the sea and became isolated islands due to the collapse of the black gear. As a result, the new Iron Isle has actually shrunk by more than half compared to the original Faitru. The Whalemon was able to move an island, and with the addition of several sets of underwater thrusters, the Iron Island was not even much slower than when the Whalemon was unloaded.

For the time being, the matter of the Iron Island is like this, all of Lu Feng's subordinates are concentrated here, and the number is more than five hundred, but unfortunately most of them are snot beasts living in underground pipelines...... The good news is that the production line in Andulumon's factory has been confirmed to have been part of the production line of the Guardianmon of the Metal Empire, and the Black Sun Goddess and Thoma are trying to restore the production line, and Ogamon has followed the Lion on to the Continent of Shaba, saying that it is to find a new subordinate for Lu Feng.

In the Iron Island, an underground city named "The Third New Tokyo City", Lu Feng signaled in the dedicated quantum channel: "Are you ready, Black Sun Goddess?"

"Everything is ready, the countdown to the teleportation starts. 5,4...... "Eve, the goddess of the black sun, had no expression on her face, cold as a machine. "1! Teleportation begins!"

Blazing blue light flashed in the device, and under the countless quantum flows, Lu Feng and Takeuchi Suna instantly turned into two streams of data and merged into the quantum stream, entering the cold routing link......

It is no longer a quantum computer that is temporarily borrowed from the crosswalk, but a quantum transmission channel built in a special laboratory, where the goddess of the black sun operates a series of instruments and computers to convert Lu Feng and Takeuchi Suna into data and send them into the online world, without even Thoma and Nanami knowing.

The Black Sun Goddess watched Lu Feng and Takeuchi Suna disappear into the quantum channel, and with a "drop" sound, her originally cold face suddenly softened, and her eyes also regained their vitality.

"Huh!?Eve, why are you here?Why didn't Angel X see him?" Nanami's video suddenly floated in and searched around.

"Eh, ah~no, I don't, you know?" said Eve, with a blank look on her face, making Nanami unable to doubt it.

"Could it be that you're going out again?" Nanami grabbed her hair, and the video shook up and down for a while, "This guy doesn't tell me every time he goes out, hmph, one day he will look good!"

Time, August evening, 1999. Location, Shibuya, Tokyo, Japan.

Takeuchi Sona appears on the roof of a commercial building, and a large book falls down at the same time. The girl wanted to memorize the big book like before, but was stopped by Lu Feng.

I saw the big book churning, floating up slowly, suspended in the air. With a "drop", a large amount of light was emitted. The light is not dazzling, it is unpredictable, and there is a certain pattern. These rays of light intertwined, and finally stabilized, forming a human figure!

Projection!

What are the main ways in which human beings, and most living things, judge the existence of a living being?

Picture, sound, smell, temperature...... So if you quantify these criteria one by one, and let a person receive these signals, he will judge whether the creature exists or does not exist?

Remember the Ogama that Yagami Taiichi met on the street? Although no one could see it, it fought the Agumon and broke through the walls of the residential buildings. In a sense, it's a projection! A projection of an Ogamon in the Digimon World!

Therefore, using the advanced light illusion technology of the Steel Empire, using 3D projection to shape the shape and convey the picture, using energy interference to convey the temperature, coupled with Lu Feng's voice, a new image was born!

Lu Feng, who had restored his original eighteen-year-old human appearance, clenched his fists: "Eighteen years old forever!" Who knows how many years I have lived?

Although it is not really a human body, it is a deceptive appearance, and Lu Feng is already very satisfied.

"Huh!?" Takeuchi Suna pointed to Lu Feng in surprise, and it took a long time before she stammered and asked, "You...... You're the right angel beast!?"

"Why, you can't recognize it if you change your appearance?" Lu Feng turned around and asked. Behind it, "Magic Laboratory" has been suspended in the air, and it looks as if Lu Feng is carrying this big book.

"Is it really the power angel beast X!?" Lu Feng's voice girl couldn't be more familiar with it, and immediately turned her surprise into joy, and began to examine Lu Feng very curiously. "Did you really become a human?" said that, he stretched out his hand and poked Lu Feng.

"Don't try, it's just a projection. Sure enough, the girl's fingers passed through Lu Feng's arm, and there was only a slight sense of blockage, and the effect of the energy field at that time, if the energy field was turned to the maximum, it could create a cylindrical space to prevent it from being discovered. In this way, the vision, hearing, temperature, and collision volume are all available, and most people can hide it.

"It's amazing!" As a result, Lu Feng's words not only failed to stop Takeuchi Suna, but instead made her start to poke Lu Feng with great interest, until Lu Feng had to turn on the collision volume, which was exempted from the treatment of ragdolls.

"August 2nd, it's only a day later than Yagami Taiichi and them, and things shouldn't have changed yet. Lu Feng's eyesight was very good, he could see the time and date from the wall clock in a building, and knew where he was at this time.

Takeuchi Suna suddenly remembered a big question: "How can I tell my family that I didn't go back last night!?"

"Don't worry!" Lu Feng hurriedly persuaded: "You should contact Taiyi and them first, and it should be okay to talk about it." ”

The huge neon lights on the building flickered non-stop, the night wind blew, and it was a little cold. Just as the two of them were about to leave, the sharp-eyed Takeuchi Suna suddenly noticed two Digimon on the traffic light, Pumpkin Monster and Ore Beast!

"It's a vampire beast's subordinate. Lu Feng didn't remember this plot very clearly, but when he was in the turbulence of time and space, his notebook wrote that the pumpkin beast and the ore beast were killed by the vampire monster because they became friends with the Ishida Yamato brothers, making the friendship badge glow.

Putting the notebook back on the shelf, Lu Feng couldn't help but sigh, memory is really a thing that comes and goes. This often doubles, and you can't tell when the memory will come back. Overall, these two Digimon are cute.

"Wow~!, this is Shibuya, which is also famous in the Digital World?" sighed Pumpkin Beast, lying on the traffic light.

"Are they Shibuya humans?" the Ore Beast immediately replied. The two cheered and rushed into the noisy crowd: "Then let's go to high together!!"

Sona Takeuchi suddenly became anxious, she was afraid that these two Digimon would harm humans. "Power Angel Beast X, let's chase it!"

Lu Feng reminded, "Now that I'm human, you should call me 'Lu Feng'!" He was very interested in what the Pumpkin Beast said just now!" Shibuya, which is also famous in the Digital World, "Is there a lot of ways to obtain information about the human world in the Digital World?" It doesn't seem to be a secret at all......