/in/foo.cc:34:9: warning: multi-character character constant [-Wmultichar]
   write('0\n');
         ^~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:30:6: warning: 'n' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int n;
      ^