You know the rules and so do I

Actually you don’t (except you read it before).

• Code should increment variable. If we have a = 0, next iteration should return 1, after that — 2, 3, 4…
• You can (and need to) describe WHY it works like this. There is no magic — only algorithms.
• It should be weird/strange/etc. Just imagine normal code with your example. If you wanna throw your PC/laptop/tablet in window — you are doing great!
• It shouldn’t be boring. a=a+1000-999 is definitely boring.
• Increment should be written in one line (maybe it will be changed later).
• No imports for your code. It should be pure JS.
  • The easiest way to test if it works — browser console.
• Supposed every code has string like a = 0 in the beginning. It’s a good idea to put it in code.
  • The variable name by default is ‘a’. You can use a different name for styling purposes.