```/* nag_complex_bessel_k (s18dcc) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nags.h>

int main(void)
{
Integer exit_status = 0;
Complex z, cy[2];
double fnu;
const Integer n = 2;
Integer nz;
char nag_enum_arg[40];
Nag_ScaleResType scal;
NagError fail;

INIT_FAIL(fail);

/* Skip heading in data file */
scanf("%*[^\n]");
printf("nag_complex_bessel_k (s18dcc) Example Program Results\n");
printf("Calling with n = %" NAG_IFMT "\n", n);
printf("   fnu           z             scal              cy[0]"
"           cy[1]      nz\n");
while (scanf(" %lf (%lf,%lf) %39s%*[^\n] ", &fnu, &z.re, &z.im,
nag_enum_arg) != EOF) {
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
scal = (Nag_ScaleResType) nag_enum_name_to_value(nag_enum_arg);

/* nag_complex_bessel_k (s18dcc).
* Modified Bessel functions K_(nu+a)(z), real a >= 0,
* complex z, nu = 0,1,2,...
*/
nag_complex_bessel_k(fnu, z, n, scal, cy, &nz, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_complex_bessel_k (s18dcc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
printf("%7.4f (%7.3f,%7.3f) %-14s (%7.3f,%7.3f) (%7.3f,%7.3f) "
"%" NAG_IFMT "\n", fnu, z.re, z.im, nag_enum_arg, cy[0].re,
cy[0].im, cy[1].re, cy[1].im, nz);
}

END:

return exit_status;
}
```