/in/foo.cc: In function 'char func(int, int)':
/in/foo.cc:14:7: warning: unused variable 'ch1' [-Wunused-variable]
  char ch1 = func(l,(l+r)/2); 
       ^~~
/in/foo.cc:16:7: warning: unused variable 'ch2' [-Wunused-variable]
  char ch2 = func((l+r)/2+1,r); 
       ^~~
/in/foo.cc:15:13: warning: 'fl' may be used uninitialized in this function [-Wmaybe-uninitialized]
   cout << fl;
             ^
/in/foo.cc:17:13: warning: 'fr' may be used uninitialized in this function [-Wmaybe-uninitialized]
   cout << fr;
             ^