Your task is to write a Python program that encrypts or decrypts a given text into/from  a secret language.

Individual words in the text are encrypted according to the following rules:

If the word starts with a vowel append 'tan' to the word.  The vowels are a, e, i, o, u.
Otherwise, take the first letter of the word, move it to the end and then append 'est'.
So:

apple becomes appletan
orange becomes  orangetan
banana becomes ananabest
python becomes ythonpest
For simplicity we'll assume that the input text is in lowercase and that it does not contain any punctuation (no commas, periods, etc...)

Your program will first ask the user to make a choice between encryption into the secret language (E) or decryption from the secret language (D).

When the user specifies 'E' for encryption, the program will translate each word in the input text into the secret language, will put the translated words in reverse order into one translated message and will print out the translated message.  The translated message will have exactly one space character between words.

When the user specifies 'D' for decryption', the program will attempt to recover  the original words from the input text.  This is only possible if the words have a specific format:  they start with a vowel and end with tan or they end with a consonant followed by est.  If one or more word does not have this format, the decryption fails and the message 'Invalid Message' is printed.

Testing:
Make sure that you test your solution before you submit it.   Here are a few test cases with the expected output.  Feel free to add your own.

Test case 1 - encryption is correct for words starting with a vowel
Please type E to encrypt or D to decrypt a message: E
Please enter your message: apple
The secret message is: appletan

Test case 2 -  encryption is correct for words starting with a consonant (non vowel)
Please type E to encrypt or D to decrypt a message: E
Please enter your message: banana
The secret message is:  ananabest

Test case 3 - encryption is correct for phrases with multiple words
Please enter your message: python is fun
The secret message is: unfest istan ythonpest

Test case 4 - encryption is correct when words are separated by more than one space character
Please enter your message: simple     is better than complex
The secret message is: omplexcest hantest etterbest istan implesest

Test case 5 - decryption is correct for words ending with 'tan'
Please type E to encrypt or D to decrypt a message: D
Please enter your message: orangetan
The secret message is: orange

Test case 6 -  decryption is correct for words ending with a consonant followed with 'est'
Please type E to encrypt or D to decrypt a message: D
Please enter your message: ryptographycest
The secret message is: cryptography

Test case 7 - decryption is correct for phrases with multiple words
Please type E to encrypt or D to decrypt a message: D
Please enter your message: omplexcest hantest etterbest istan implesest
The secret message is: simple is better than complex

Test case 8 - The user is repeatedly prompted for input until they enter a valid choice (E or D)
Please type E to encrypt or D to decrypt a message: K
Invalid choice
Please type E to encrypt or D to decrypt a message: x
Invalid choice
Please type E to encrypt or D to decrypt a message: e
Invalid choice
Please type E to encrypt or D to decrypt a message: E
Please enter your message: hello
The secret message is: ellohest

Test case 9 - An invalid message is not decrypted
Please type E to encrypt or D to decrypt a message: D
Please enter your message: this is fun
Invalid Message