/in/foo.c:1:9: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
 include <stdio.h>
         ^
In file included from /in/foo.c:2:0:
/usr/include/stdlib.h:100:8: error: unknown type name 'size_t'
 extern size_t __ctype_get_mb_cur_max (void) __THROW __wur;
        ^~~~~~
/usr/include/stdlib.h:427:22: error: unknown type name 'size_t'
 extern void *malloc (size_t __size) __THROW __attribute_malloc__ __wur;
                      ^~~~~~
/usr/include/stdlib.h:429:22: error: unknown type name 'size_t'
 extern void *calloc (size_t __nmemb, size_t __size)
                      ^~~~~~
/usr/include/stdlib.h:429:38: error: unknown type name 'size_t'
 extern void *calloc (size_t __nmemb, size_t __size)
                                      ^~~~~~
/usr/include/stdlib.h:441:36: error: unknown type name 'size_t'
 extern void *realloc (void *__ptr, size_t __size)
                                    ^~~~~~
/usr/include/stdlib.h:716:9: error: unknown type name 'size_t'
         size_t __nmemb, size_t __size, __compar_fn_t __compar)
         ^~~~~~
/usr/include/stdlib.h:716:25: error: unknown type name 'size_t'
         size_t __nmemb, size_t __size, __compar_fn_t __compar)
                         ^~~~~~
In file included from /usr/include/stdlib.h:720:0,
                 from /in/foo.c:2:
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h:20:49: error: unknown type name 'size_t'
 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: error: unknown type name 'size_t'
 bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
                                                                 ^~~~~~
In file included from /in/foo.c:2:0:
/usr/include/stdlib.h:725:34: error: unknown type name 'size_t'
 extern void qsort (void *__base, size_t __nmemb, size_t __size,
                                  ^~~~~~
/usr/include/stdlib.h:725:50: error: unknown type name 'size_t'
 extern void qsort (void *__base, size_t __nmemb, size_t __size,
                                                  ^~~~~~
/usr/include/stdlib.h:823:36: error: unknown type name 'size_t'
 extern int mblen (const char *__s, size_t __n) __THROW;
                                    ^~~~~~
/usr/include/stdlib.h:827:34: error: unknown type name 'size_t'
      const char *__restrict __s, size_t __n) __THROW;
                                  ^~~~~~
/usr/include/stdlib.h:834:8: error: unknown type name 'size_t'
 extern size_t mbstowcs (wchar_t *__restrict  __pwcs,
        ^~~~~~
/usr/include/stdlib.h:835:32: error: unknown type name 'size_t'
    const char *__restrict __s, size_t __n) __THROW;
                                ^~~~~~
/usr/include/stdlib.h:837:8: error: unknown type name 'size_t'
 extern size_t wcstombs (char *__restrict __s,
        ^~~~~~
/usr/include/stdlib.h:838:38: error: unknown type name 'size_t'
    const wchar_t *__restrict __pwcs, size_t __n)
                                      ^~~~~~
/in/foo.c: In function 'main':
/in/foo.c:8:5: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
     scanf("%d %d %d",&N,&M,&Q);
     ^~~~~
/in/foo.c:8:5: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:8:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:40:5: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
     printf("%d\n",k);
     ^~~~~~
/in/foo.c:40:5: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:40:5: note: include '<stdio.h>' or provide a declaration of 'printf'