encrypted text is as follows:

bibox whx, nb rqhulb yqb nzokw, mdy yz rqhulb yqb nzokw vu h nhx yqhy pbhut huxyqvul, yqhy yhfbt pzob yvpb yqhu pzty ebzekb qhib. vy ubibo qheebut hkk hy zurb. vyt tkzn. vyt pbyqzwvrhk. vyt bsqhdtyvul. nb wzuy hkk qhib yqb tyzphrq gzo vy.

whbpzut, yqbx rhkk yqbp. yqbx ebogzop hryvzu nvyqzdy dtbo vuybohryvzu. pzuvyzovul, kzllvul, uzyvgvrhyvzut. eovphk dolbt, obeobttbw pbpzovbt, durzutrvzdt qhmvyt. yqbxob hknhxt yqbob, hknhxt hryvib. nb rhu yox yz mb ovlqy, nb rhu yox yz mb lzzw. nb rhu yox yz phfb h wvggboburb, mdy vyt hkk h kvb. rhdtb vuybuyvzut hob voobkbihuy. yqbx wzuy wovib dt. whbpzut wz.

pzty rzwbot yqvuf wbmdllvul tzgynhob vt hmzdy gvsvul h pvtyhfb, mdy yqhyt uzutbutb. wbmdllvult hrydhkkx hkk hmzdy gvuwvul yqb mdl, hmzdy duwbotyhuwvul nqx yqb mdl nht yqbob yz mblvu nvyq, hmzdy fuznvul yqhy vyt bsvtyburb nht uz hrrvwbuy. vy rhpb yz xzd yz wbkvibo h pbtthlb, kvfb hu durzutrvzdt mdmmkb gkzhyvul yz yqb tdoghrb, ezeevul nvyq h obibkhyvzu xzdib tbrobykx fuznu hkk hkzul. h tvpekb eozlohp, h nzop yqhy rhu phfb whyh duobhwhmkb, phknhob yqhy yzzf Whokbub phxmb ynz qzdot yz rzwb. vt yqhy obhkkx hkk vy yhfbt yz fvkk yqb nzokw?

yqb rzurbey zg nhvyvul mbnvkwbot pb. yqbob hob hknhxt wbhwkvubt. yqbob hob hknhxt yvrfvul rkzrft. yqhyt nqx xzd pdty phuhlb xzdo yvpb.

tdob, yqbob hob lohxt, mdy nqbu xzd rzpb ovlqy wznu yz vy, hy vyt rzob, mbubhyq bibox rqzvrb, yqbobt bvyqbo h zub zo h cboz. xzd bvyqbo wz tzpbyqvul zo xzd wzuy. xzd nhkf zdy yqhy wzzo, xzdib wbrvwbw yz wz uzyqvul, yz thx uz, nqvrq pbhut xzd wz uzy rzpb mhrf. xzd kbhib, xzd hob uz kzulbo h ehoy zg yqvt. xzd mbrzpb h cboz. vg xzd tyhx, vg xzd nhuy yz rqhulb yqb nzokw, xzd mbrzpb h xbt. xzd mbrzpb h zub. tz, vkk htf xzd hlhvu: hob xzd h zub zo h cboz?

rqzvrbt. phxmb po. ozmzyt ovlqy. yqhyt nqhy yqvt vt hkk hmzdy, yqb xbttbt huw uzt zg kvgb. mdy wz nb wbrvwb yqbp zo wz yqbx wbrvwb dt?

Ask the user to enter the decryption key. Repeat the request until the right key is entered. Display a message when file decryption is over. Ask the user to enter a key to re-encrypt the file. Re-encrypt file "decrypted.txt" and store it at "encrypted.txt" Display a message when file encryption is over. Only alphabet letters (uppercase/lowercase) must be encrypted. The remaining characters (question marks, periods. etc. must remain intact). Your code must be modular. Use the following function prototypes for encryption and decryption: char encrypt Fun(int a, int b, char letter); // This function receives as input the key components (0,3) and the plaintext letter and returns the encrypted letter. char decryptFun(int a, int b, char letter); // This function receives as input the key components (Q.B) and an encrypted letter and returns the decrypted letter. int inverse(int x); // This function as input receives an int x and returns the multiplicative inverse of I modulo 26. You are also given the following function that correctly implements the modulo operation for both positive and negative numbers int mod (int , int y){ while(