you're right. but this programming is for fun, not real development. no one writes this in an important part of the real project

Code is obviously very concise, but lacks serious readability. Use more descriptive variables. Just something that gives other people reading the code a better idea of what the code does. This will be quite important when you ever write code that will eventually be used by other devs.

This is what they mean when they say "Think Differently."