Help me to code this plz.. (for billing system)

Question

I want to take 4 digit number as user input.first two digits represent the account type of the user.and also i want to print "enter vaid id,if the user enter a number with less than or greater than 4 digit number..

Answer 1

Hint:
• Use do-while loop because it is likely that you'll have to prompt for a number at least once.
• Use `if` to check whether the number was within 4 digit numbers range.