Because this question does not consider the meaning of K, I want you to consider it from two aspects and look at your brain thinking.

I am a teacher of Jiangsu college entrance examination. If I know anything, you can come to Baidu to ask questions. I can help you solve these puzzles at any time.

There is also this problem that allows you to express that k=0 and k do not exist in the process of solving.

Whether this question is 5 or 10, if you can express these two questions in the process of solving, you will get extra points.

↖(^ω^)↗