Run the Program: Execute the script using a Python interpreter.
Choose Operation: Enter encrypt to encrypt a message or decrypt to decrypt a message.
Input Message: Provide the text you want to process.
Enter Shift Value: Specify the shift value (an integer).
Get Result: The program outputs the encrypted or decrypted message.
Example For a message "Hello, World!" with a shift value of 3:
Encrypted: "Khoor, Zruog!"
Decrypted: "Hello, World!"