/in/foo.cc: In function 'int main()':
/in/foo.cc:14:15: warning: 'grade' may be used uninitialized [-Wmaybe-uninitialized]
   14 |         printf("%c\n",grade);
      |         ~~~~~~^~~~~~~~~~~~~~
/in/foo.cc:6:14: note: 'grade' was declared here
    6 |         char grade;
      |              ^~~~~