Write a program (programs) that prompts you to add a username to a sequence (collection) of stored names. The name of the program is user_check+your student ID + version number with a .py extension.

It must continuously prompt for more user names until a condition, such as typing 'exit' is met. The company you work for has a policy that says "no characters such as "\#, %% or digits such as 1,2,3,4,5,6,7 are ever used in usernames," and all characters other than letters are filtered (see Version One and Version Two below for further detail). "4w"At any given time, you're able to see current users. Comment your code appropriately. Version One: A 'for loop' is used to filter out unwanted characters; a STRING is used to store, add, and maintain users. This is to be referred to as 'Routine A ' in your comments. Version Two: You must NOT use a 'for loop.' Like Routine A, a STRING is used to store, add, and maintain users. This is to be referred to as 'Routine B' in your comments. Version Three: A 'for loop' is used to filter out unwanted characters; a LIST (array) is used to store, add, and maintain users. This is to be referred to as 'Routine C ' in your comments. Version Four: You must NOT use a 'for loop.' Like Routine A, a LIST (array) is used to store, add, and maintain users. This is to be referred to as 'Routine D' in your comments