C++ programming. code needs to output sample

The Affine cipher is a cryptographic method for encrypting text such that it becomes unreadable to a party without access to the cryptographic key. The encryption and decryption operations are simple shifts of the alphabet letters in a cyclic fashion. Mathematically, for a key k-(a, 3), the encryption and decryption are defined as: Encryption: c-(a r B) mod 26, 1Sa 26 and 1SB 26 Decryption: x = a-1, (c-d) mod 26. Here, 1 is a multiplicative inverse of a in the group of integers modulo 26. To find the multiplicative inverse of one needs to find z such that a -1 mod 26 A simple way of finding the inverse of a is to consider all numbers from 1 to 25 and see which one satisfies equation To illustrate the use of the Affine cipher, consider the encryption of "defend the east wall of the castle" with key k = (, ) = (5,7). The first letter "d is mapped to number 3 (alphabet letters are numbered from 0 to 25). Inserting 3 to the encryption functions yields c 5 * 3 + 7 mod 26-22 mod 26-22 which corresponds to letter "w". Applying the same process for ever letter, the plaintext sentence is translated to "wbgbuw yqb bhty nhkk zg yqb rhtykb" . Now to decode, we first need to find the inverse of 5 modulo 26. Scanning every number from 1 to 25, we observe that 5-21 mod 26 so the inverse of 5 is 21. Using 21 for decrypting the first letter "" (or 22) becomes 21 (22-7) mod 263, which reverses back to letter "d NOTE: The modulo operation for negative numbers is different from the % arithmetic operator in C. Write a C program that decrypts a file named "encrypted.txt" and places the decryption output to a file called "de- crypted.txtA file encrypted with k (5,7) is provided with the assignment. You can use it to test your decryption function. You will know when you have succeeded because the text becomes readable. In your program