Lu Ren was speechless for a moment, staring blankly at the boy's back as he walked away.

It wasn't until the thin figure disappeared from the corner of the stairs that he finally came to his senses.

He pounded the wall hard, feeling grief-stricken, indignant, and furious.

Aaaaahhh!!!

Is there a difference between one night and two nights?

Is there any difference?

God, you are so unfair!

There are so many geniuses in the world, why can't there be one like me, Lu Ren!

On the third day, Lu Qi kept his promise and came out of the laboratory holding a few brown pencils.

He has a quirk. He concentrates on what he is doing and has to finish it once he is done, otherwise he will feel uneasy.

So, without even tidying up his appearance, he went straight to the teacher's office to hand in his research results.

"Teacher, the pencil has been developed."

“Okay, okay!”

"Lu Qi, you are worthy of being the genius of my engineering school!"

The teacher was overjoyed and praised repeatedly.

After the excitement subsided, he curiously picked up a pencil and tried to write.

Although he was a little uncomfortable using it the first time and his handwriting was crooked, after getting used to it, he could easily write a neat line of words.

"Excellent! It really can be written!"

The teacher's face became more and more joyful, and his heart was filled with pride and honor.

Suddenly, he noticed a "two" mark on the pencil out of the corner of his eye and was surprised.

"Huh? Why is there a mark?"

"Oh, this mark represents the shade of color, one is the lightest and five is the darkest."

"Pencils of different shades can be used for writing, drawing, and marking construction..."

Lu Qi said it calmly, as if this clever idea was just a trivial matter.