Imagine you are developing a software package that requires users to enter their own passwords. Your software requires that users' passwords meet the following criteria:
• The password should be at least six characters long.
• The password should contain at least one uppercase and at least one lowercase letter.
• The password should have at least one digit. Write a program that asks for a password and then verifies that it meets the stated criteria. If it doesn't, the program should display a message telling the user why.