/in/foo.cc: In function 'int sbteacher(int)':
/in/foo.cc:36:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:39:9: warning: unused variable 'hh' [-Wunused-variable]
     int hh=0;
         ^~
/in/foo.cc:40:9: warning: unused variable 'vs' [-Wunused-variable]
     int vs=0;
         ^~