Overview
Write a Python program to check the validity of password input by users:
Passwords MUST contain the following:
At least 1 letter between [a-z] and 1 letter between [A-Z]. At least 1 number between [0-9]. At least 1 character from [$#@]. Minimum length 6 characters. Maximum length 16 characters.
Also, each of the above checks should be written as a function