It is vitally important that your program never "crash" as a result of a menu selection, regardless of what the user have chosen to do. To clarify, if the user chooses to increase the length of a sequence and no sequences are currently in the database, your program must print an error message but it must not crash. Similarly, if a user has loaded a sequence with 0 values (i.e., an empty list) and then asks to decrease its length by 1, the program must print an error message but it must not crash.