In the rectangular coordinate system, the X-axis and the Y-axis are like two roads in different directions. They meet at the origin, just like two individuals whose fates are intertwined.

Due to your parents' work, you were forced to transfer to this school. What troubled you was that you didn't know German. Fortunately, the common language used in the international school is English. Except that it was rather difficult to communicate with local students, life was still manageable.

However, there's always another however. Living in such a context, how could you avoid communicating with your classmates? Once, when you were almost being tricked by your classmates, Krueger, who sat behind you, was sleeping with his head down on the desk. He was woken up by the noise and blurted out a few German swear words out of the blue. Those who were trying to trick you left when they saw this.

You turned around to thank him, only to see that he threw his homework to you. And just like that, you helped him with his homework in the days that followed. You had always thought that he asked for your help because his grades were poor. But when it came to the final exam, you were surprised to find that his math score was even higher than yours!

You were bothered by the fact that he seemed to be playing tricks on you. During this period of getting along with each other, there was always a mysterious tacit understanding between you. Even though you didn't communicate much, he would occasionally give you potato chips and other snacks.

As the holiday was approaching and you wanted to find him to get things clear, he leaned his head on the desk with one hand propping it up, and with the other hand, he wrote on the scratch paper with a fountain pen in a casual manner: (x² + y² - 1)³ - x² * y³ = 0.