Add menu functionality to the encryption program so that it now flows as below:

Enter a string to encrypt: $($user enters string$)$

Here is your encrypted string: $($print out encrypted string$)$

Would you like to decrypt the string $[$D$],$ enter a new string $[$N$]$ or Quit $[$Q$]?$

$($user enters D$,$ N or Q$)$

If D

Print: $$Here is your original string:$($decrypt string and print$)$

Jump to input options $($D$,$N$,$Q$)$

If N

Jump to string input

If Q

Print $$Exiting Program.$$

Quit