Write a Python program to check the validity of password input by users. Allow a user 3 attempts, on the 4th one exit the program(Google is your friend :)).

Validation : At least 1 letter between [a-z] and ta least one letter between [A-Z]. At least 1 number between [0-9]. At least 1 character from [$#@]. Minimum length 6 characters. Maximum length 16 characters.

Your messages should be like this: 1. Please enter your password: "your pwd" 2. Your pwd is invalid! 3. Your pwd is valid! 4. You have entered your pwd 3 times and exceeded the limit!