Given input as a text file (.txt), encrypt and decrypt the text in the file using RSA encryption and decryption. How do I achieve the solution?

Part 1:
Input format:
Your program should prompt the user for the following input:
Enter the input file that you want to encrypt:

Program functionality:
The program should:
Select two large primes at random, p and q
Compute n = p x q
Select at random encryption key e
Find decryption key d
Your program must be able to:
Convert each character in the message into ASCII code
Print p, q, e, and d on the screen
Encrypt the message using key {e, n}
Print the encrypted message on the screen
Decrypt the text using key {d, n}
Print the decrypted message on the screen
Part 2:
To check the correctness of the program, the program will accept p, q, and e from keyboard.
In part 2, your program should prompt the user for the following input:
Enter the input file that you want to encrypt:
Enter p :
Enter q:
Enter e:
 \program must be able to:
Convert each character in the message into ASCII code
Encrypt the message using key {e, n}
Print the encrypted message on the screen
Decrypt the text using key {d, n}
Print the decrypted message on the screen
Note:
The text file contains only the letters A-Z and a-z.