foo.c: In function ‘main’:
foo.c:7:9: warning: implicit declaration of function ‘scanf_s’; did you mean ‘scanf’? [-Wimplicit-function-declaration]
    7 |         scanf_s("%d",&m);
      |         ^~~~~~~
      |         scanf
foo.c: At top level:
foo.c:21:12: error: expected declaration specifiers or ‘...’ before string constant
   21 |     printf("hello, world\n");
      |            ^~~~~~~~~~~~~~~~
foo.c:22:1: error: expected identifier or ‘(’ before ‘}’ token
   22 | }
      | ^