$1.$Ask the user to enter the username and password for an account they would like to sign into.

$2$a$.$ Check if an account exists that has the username the user entered $($make a method that does this$),$ and then retrieve & decrypt the password for that account if it exists.

$2$b$.$ Attempt to retrieve & decrypt the password associated with the username entered by the user. If a password isn$$t found in the database, there is no user with the username that was entered. Hint: make a modified version of retrievePasswordFromDatabase that has a $$username$$ parameter. $3.$ Lastly, compare the decrypted password to the password that was just entered by the user. If the passwords match, print $$Sign In Successful!$.$ If they don$$t match, print $$Incorrect Password!$$ Let$$s assume that every $$username$$ is completely unique $($kind of like it$$s a primary key$).$