answer.code:1:9: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘<’ token
    1 | include <stdio.h>
      |         ^
In file included from answer.code:2:
/usr/include/stdlib.h:97:8: error: unknown type name ‘size_t’
   97 | extern size_t __ctype_get_mb_cur_max (void) __THROW __wur;
      |        ^~~~~~
/usr/include/stdlib.h:539:22: error: unknown type name ‘size_t’
  539 | extern void *malloc (size_t __size) __THROW __attribute_malloc__
      |                      ^~~~~~
/usr/include/stdlib.h:56:1: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
   55 | #include <bits/floatn.h>
  +++ |+#include <stddef.h>
   56 | 
/usr/include/stdlib.h:542:22: error: unknown type name ‘size_t’
  542 | extern void *calloc (size_t __nmemb, size_t __size)
      |                      ^~~~~~
/usr/include/stdlib.h:542:22: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:542:38: error: unknown type name ‘size_t’
  542 | extern void *calloc (size_t __nmemb, size_t __size)
      |                                      ^~~~~~
/usr/include/stdlib.h:542:38: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:550:36: error: unknown type name ‘size_t’
  550 | extern void *realloc (void *__ptr, size_t __size)
      |                                    ^~~~~~
/usr/include/stdlib.h:550:36: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:821:9: error: unknown type name ‘size_t’
  821 |         size_t __nmemb, size_t __size, __compar_fn_t __compar)
      |         ^~~~~~
/usr/include/stdlib.h:821:9: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:821:25: error: unknown type name ‘size_t’
  821 |         size_t __nmemb, size_t __size, __compar_fn_t __compar)
      |                         ^~~~~~
/usr/include/stdlib.h:821:25: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
In file included from /usr/include/stdlib.h:825,
                 from answer.code:2:
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h:20:49: error: unknown type name ‘size_t’
   20 | bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
      |                                                 ^~~~~~
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h:1:1: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
  +++ |+#include <stddef.h>
    1 | /* Perform binary search - inline version.
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h:20:65: error: unknown type name ‘size_t’
   20 | bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
      |                                                                 ^~~~~~
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h:20:65: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
In file included from answer.code:2:
/usr/include/stdlib.h:830:34: error: unknown type name ‘size_t’
  830 | extern void qsort (void *__base, size_t __nmemb, size_t __size,
      |                                  ^~~~~~
/usr/include/stdlib.h:830:34: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:830:50: error: unknown type name ‘size_t’
  830 | extern void qsort (void *__base, size_t __nmemb, size_t __size,
      |                                                  ^~~~~~
/usr/include/stdlib.h:830:50: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:922:36: error: unknown type name ‘size_t’
  922 | extern int mblen (const char *__s, size_t __n) __THROW;
      |                                    ^~~~~~
/usr/include/stdlib.h:922:36: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:926:34: error: unknown type name ‘size_t’
  926 |      const char *__restrict __s, size_t __n) __THROW;
      |                                  ^~~~~~
/usr/include/stdlib.h:926:34: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:933:8: error: unknown type name ‘size_t’
  933 | extern size_t mbstowcs (wchar_t *__restrict  __pwcs,
      |        ^~~~~~
/usr/include/stdlib.h:934:32: error: unknown type name ‘size_t’
  934 |    const char *__restrict __s, size_t __n) __THROW;
      |                                ^~~~~~
/usr/include/stdlib.h:934:32: note: ‘size_t’ is defined in header ‘<stddef.h>’; did you forget to ‘#include <stddef.h>’?
/usr/include/stdlib.h:936:8: error: unknown type name ‘size_t’
  936 | extern size_t wcstombs (char *__restrict __s,
      |        ^~~~~~
/usr/include/stdlib.h:937:38: error: unknown type name ‘size_t’
  937 |    ...