Need some help writing a program that will take an input.txt and then encrypt that input.txt by taking whatever is inside of it ann remove any duplicate letters from that word. Then append to the text the remaining letters in the alphabet in reverse alphabetical order. ie. Unknown would become UNKOWZYXVTSRQPMLJIHGFEDCBA I need the program to be able to encrypt and decrypt. I have no idea how I would encrypt the file I know how to take the input.txt and an output.txt thats the easy part. Any help would be appreciated.