for(int i = 0, j = 1, m = strlen(p); i < m; i++, j++)
{

        if(isalpha(p[i]))
        {
            if(isupper(p[i]))
            {
                kl = strlen(argv[1]);
                int answer1 = ((p[i] - 'A') + (argv[1][j % kl] - 'A')) %26 + 'A';

                printf("%c",answer1);
                /*
                *The ASCII integer of A must be subtracted from the ith character in the plaintext in order to make
                *that character 0 and then later added back in order to give its ASCII value back.
                */
            }