This is a reverse coding challenge. Normally you're given explicit directions with how to create a function. Here, you must generate your own function to satisfy the relationship between the inputs and outputs.
Your task is to create a function that, when fed the inputs below, produces the sample outputs shown.
mystery_func(152) ➞ 10
mystery_func(832) ➞ 48
mystery_func(19) ➞ 9
mystery_func(133) ➞ 9N/A