/in/foo.c: In function 'main':
/in/foo.c:7:6: warning: unused variable 'n' [-Wunused-variable]
  int n;
      ^
/in/foo.c:22:12: warning: 'sun' may be used uninitialized in this function [-Wmaybe-uninitialized]
         sun+=h;
         ~~~^~~