One of these is true and the other is very not true. Did you guess correctly? 🤔 So, how do we test Kaprekar’s constant by brute force? Well, there are 9999 possible 4 digit numbers between 0001 and 9999, but we can’t use numbers with four of the same digit, like 1111 or 2222, so that brings us down to 9990. Good start 💪🏽 We only need to check the numbers with digits that are already descending. For example if we check 4321 we don’t need to check 4231 or 4123 or any of the other 22 numbers tha