/in/foo.cc: In function 'int read()':
/in/foo.cc:8:10: warning: variable 'flag' set but not used [-Wunused-but-set-variable]
  int x=0,flag=1;
          ^~~~
/in/foo.cc:21:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^