Kata

While most devs know about big/little-endianness, only a selected few know the secret of real hard core coolness with mid-endians.

Your task is to take a number and return it in its mid-endian format, putting the most significant couple of bytes in the middle and all the others around it, alternating left and right.

For example, consider the number 9999999, whose hexadecimal representation would be 98967F in big endian (the classic you get converting); it becomes 7F9698 in little-endian and 96987F in mid-endian.

Write a function to do that given a positive integer (in base 10) and remembering that you need to pad with 0s when you get a single hex digit!