/in/foo.cc: In function 'int main()':
/in/foo.cc:7:6: warning: unused variable 'a' [-Wunused-variable]
  int a,k,x;
      ^
/in/foo.cc:12:7: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout <<k;
  ~~~~~^~~