/in/foo.c: In function 'main':
/in/foo.c:33:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~
/in/foo.c: At top level:
/in/foo.c:38:6: error: redefinition of 'main'
 }int main()
      ^~~~
/in/foo.c:29:5: note: previous definition of 'main' was here
 int main()
     ^~~~
/in/foo.c: In function 'main':
/in/foo.c:42:12: warning: zero-length gnu_printf format string [-Wformat-zero-length]
     printf("");
            ^~