/in/foo.cc: In function 'int main()':
/in/foo.cc:8:8: warning: unused variable 'y' [-Wunused-variable]
  int x,y,xx,cnt;
        ^
/in/foo.cc:8:10: warning: unused variable 'xx' [-Wunused-variable]
  int x,y,xx,cnt;
          ^~
/in/foo.cc:17:11: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<cnt;
           ^