/in/foo.cc: In function 'int main()':
/in/foo.cc:5:2: error: 'cin' was not declared in this scope
  cin>>n;
  ^~~
/in/foo.cc:25:3: error: 'cout' was not declared in this scope
   cout<<x;
   ^~~~
/in/foo.cc:27:3: error: 'cout' was not declared in this scope
   cout<<z;
   ^~~~
/in/foo.cc:29:3: error: 'cout' was not declared in this scope
   cout<<y;
   ^~~~